CN100543595C - Positively chargeable developer - Google Patents

Abstract

The invention provides a kind of developer,, and can obtain stable image quality even its long-term use does not produce image deflects yet.A kind of Positively chargeable developer, it has Positively chargeable toner-particle, silica and inorganic micro powder end at least, this Positively chargeable toner-particle contains binding resin, magnetic oxide at least, it is characterized in that, the nothing constraint yield strength of this developer when primary consolidation stress 5kPa is 0.1～2.5kPa, and the nothing constraint yield strength of this developer when primary consolidation stress 20kPa is 2.5～5.5kPa.

Description

Positively chargeable developer

Technical field

The image forming method and the image processing system that the present invention relates to be used for electrofax and penetrate the developer of powder ink-jet and be used to make electrostatic image development.

Background technology

In the past, as the image forming method, known electrostatic recording, magnetography, penetrated many methods such as powder ink-jet (toner jet) method.For example, known as xerography as No. the 2297691st, United States Patent (USP), many methods of being put down in writing for Japanese Patent Publication 42-023910 number and Japanese Patent Publication 43-24748 number, these normally utilize the photoconductivity material, on photoreceptor, form electrostatic latent image by various means, then, with toner to this sub-image formation visual image that develops, as required toner is transferred on the transfer materials such as paper, the method that toner image is obtained duplicating thing to the transfer printing material by thermal pressure etc. then, so, the toner that does not have transfer printing and remain on the photoreceptor is cleaned by the whole bag of tricks, repeats above-mentioned operation.

In recent years, such copy device begins to require harshly more miniaturization, more lightweight and more high speed, higher reliability.For example, not only be the issued transaction duplicating machine that original draft is duplicated in usually said being used to, begin to be used to duplicating purposes and require more the light printing (can utilize PC to carry out the purposes that prints on demand of a small amount of printing of many kinds of duplicating, binding from being edited into of file) of reliability as the digital printer of the output of computer or the contour careful image of graphic designs.For this reason, require higher meticulous, high image quality as picture quality, the result also becomes higher to the desired performance of toner.

For example, in Japanese kokai publication hei 7-230182 number and Japanese kokai publication hei 8-286421 grade, proposed to add the magnetic powder and made the stable scheme of charging property by the outside.According to this method, really not only can obtain the stable toner of charging property, and can obtain the high toner of spatter property, but require in desired high speed in recent years and as picture quality in the purposes of higher meticulous, high image quality, not only development property is insufficient, also take place the adhering to of live part etc., still insufficient.In addition, add the scheme that charged mitigator suppresses the superfluous charged of toner and keeps high image quality in the special fair 6-093136 of Japan number and Japanese special fair 6-093137 number, having proposed by the magnetic color tuner of having stipulated size-grade distribution.Further, in Japanese kokai publication hei 8-137125 number, proposed by making inorganic particles adhere to the surface of toner master batch, the zeta potential difference of toner master batch surface and toner surface is reached more than the certain value, improve electric charge uneven of toner surface and obtain uniform charged scheme.In addition, in TOHKEMY 2001-034006 number and TOHKEMY 2002-0207314 grade, proposed by controlling specific inorganic particles can obtain the good toner of charging property to the coverage rate of toner surface, from the ionization rate of toner surface scheme.In addition, in TOHKEMY 2003-280253 number, TOHKEMY 2003-280254 number, Japanese kokai publication hei 4-083258 number, Japanese kokai publication hei 4-083259 number, Japanese kokai publication hei 4-142560 number, Japanese kokai publication hei 4-269763 number and Japanese kokai publication hei 4-350665 number, proposed by in toner, add the fine magnesium oxide micro-powder end improve mobile, thereby charging property is good and can reduce the scheme of environmental factor dependence.

These motions all produce effect aspect the charging property improving, but in desired high speed in recent years and require the purposes of higher meticulous, high image quality as picture quality, even just requiring also to leave the leeway of improvement in the purposes that using method that toner worsens also obtains high reliability and stable picture quality for taking place easily because of high speed printing.

Summary of the invention

The object of the present invention is to provide developer that has overcome the problems referred to above point and the image forming method that uses this developer.

Even the object of the present invention is to provide the long-term image forming method that does not also produce image deflects and can obtain the developer of stable image quality and use this developer that uses.

The present invention is a kind of Positively chargeable developer, and it has the Positively chargeable toner-particle at least, and this Positively chargeable toner-particle contains binding resin, magnetic oxide at least, it is characterized in that,

The nothing constraint yield strength (U of this developer when primary consolidation stress 5.0kPa _5kPa) be 0.1kPa≤U _5kPa≤ 2.5kPa,

The nothing constraint yield strength (U of this developer when primary consolidation stress 20.0kPa _20kPa) be 2.5kPa≤U _20kPa≤ 5.5kPa.

In addition, the preferred outside inorganic micro powder end of adding in this Positively chargeable toner-particle of developer of the present invention.

In addition, in the present invention, preferably this inorganic micro powder end is for being selected from the micropowder of at least a kind of oxide in zinc paste, aluminium oxide, the magnesium oxide.

In addition, in the present invention, preferred this inorganic micro powder end is the fine magnesium oxide micro-powder end, and (2 θ ± 0.2deg) there is the crystallographic system at peak at the 42.9deg place, and (half breadth at the X-ray diffraction peak at 2 θ ± 0.2deg)=42.9deg place is below the 0.40deg at this Bragg angle for the Bragg angle in CuK α characteristic X-ray diffraction at this fine magnesium oxide micro-powder end.

In addition, in the present invention, preferably the volume average particle size at this fine magnesium oxide micro-powder end (A) is 0.1 μ m≤A≤2.0 μ m,

Size-grade distribution is: the following volume distributed median accumulated value of 1/2 times of particle diameter of this volume average particle size is below the 10 volume %, and the above volume distributed median accumulated value of 2 times of particle diameters of this volume average particle size is below the 10 volume %.

In addition, in the present invention, preferably the isoelectric point at this fine magnesium oxide micro-powder end is 8～14.

In addition, in the present invention, preferably the specific surface area at this fine magnesium oxide micro-powder end is 1.0～15.0m ²/ g.

In addition, in the present invention, preferably the MgO content in this fine magnesium oxide micro-powder end is more than 98.00%.

In addition, in the present invention, the content (B) at preferred inorganic micro powder end is 0.01 quality %≤B≤2.00 quality % based on whole developers.

In addition, in the present invention, the ionization rate (C) at preferred inorganic micro powder end is 0.1%≤C≤5.0%.

In addition, in the present invention, the zeta potential that preferably the Positively chargeable toner-particle is distributed to this Positively chargeable toner-particle under the pH of the dispersion liquid that forms in the water is below the 40mV with difference with the zeta potential at this inorganic micro powder end under the pH.

In addition, in the present invention, preferred developer also contains the silica micropowder except that containing the inorganic micro powder end.

In addition, in the present invention, when preferably measuring this silica micropowder to the wettability of methanol mixed solvent with the transmissivity of 780nm wavelength light, transmissivity is that 80% o'clock methanol concentration (D) is 65 volume %≤D≤80 volume %.

In addition, the preferred acid number (D of this developer of developer of the present invention _Av) be 0.5mgKOH/g≤D _Av≤ 20.0mgKOH/g.

In addition, developer of the present invention is in the size-grade distribution of benchmark with the number what measure with 256 passages by Coulter counter preferably, and half breadth Y satisfies following formula to peak granularity X:

2.06×X-9.0≤Y≤2.06×X-7.5

In addition, in the molecular weight distribution of the solvable composition of THF in the preferred developer of developer of the present invention by gel permeation chromatography (GPC) mensuration, at molecular weight is that there is main peak in the zone below 30000 more than 3000, and the peak area of molecular weight below 100,000 is more than the 70 quality % with respect to all peak areas.

In addition, when developer of the present invention preferably carried out extraction in 16 hours by the Soxhlet extractron that uses tetrahydrofuran (THF) to this developer, the insoluble composition of the THF of this binding resin composition was the insoluble composition of 0.1 quality %≤THF≤50.0 quality %.

In addition, the preferred binding resin of developer of the present invention has the polystyrene copolymer resins at least.

In addition, developer of the present invention preferably has charge control agent, and this charge control agent is at least a kind in triphenylmethane compound, the quaternary ammonium salt.

In addition, in the present invention, preferably this magnetic oxide has octahedra shape and/or multinuclear shape.

In addition, in the present invention, the content (E) of preferred magnetic iron oxide particle is 20 mass parts≤E≤200 mass parts with respect to 100 mass parts binding resins.

Further, the present invention is a kind of image forming method, it is characterized in that, it has developing procedure at least, and this developing procedure keeps the electrostatic latent image on the body to develop by being formed at the developer layer on the developer carrier to being formed at sub-image, thereby form the developer image, wherein

The torque (T) that puts on this developer carrier of the state that is formed with developer layer is 0.1Nm≤T≤50Nm,

This developer is for having the Positively chargeable developer of Positively chargeable toner-particle at least, and this Positively chargeable toner-particle contains binding resin, magnetic oxide at least, the nothing constraint yield strength (U of this developer when primary consolidation stress 5kPa _5kPa) be 0.1kPa≤U _5kPa≤ 2.5kPa,

The nothing constraint yield strength (U of this developer when primary consolidation stress 20kPa _20kPa) be 2.5kPa≤U _20kPa≤ 5.5kPa.

In addition, image forming method of the present invention preferably this sub-image keep body to possess the photoconductive layer that comprises amorphous silicon at least on conductive base, this conductive base, the sealer that comprises amorphous silicon and/or agraphitic carbon and/or amorphous silicon nitride on this photoconductive layer.

Description of drawings

Fig. 1 is the sketch that is illustrated in an example of the image processing system that is suitable for when using developer of the present invention to carry out image formation.

Fig. 2 is the sketch that is illustrated in an example of the image processing system that is suitable for when using developer of the present invention to carry out image formation.

Fig. 3 is expression primary consolidation stress and the figure that does not have the relation of constraint yield strength.

Fig. 4 is an example of the size-grade distribution of the 256G passage that obtained by Coulter Multisizer IIE (production of Coulter company) of expression.

Fig. 5 is the explanation sketch of fixing device.

Embodiment

People of the present invention study the composition material that is used for developer, find that by the powder characteristics of control Positively chargeable developer under concretion state, developer can not worsen in long-term the use yet, can obtain stable image quality.

And people of the present invention find, the powder characteristics of Positively chargeable developer under concretion state can contain the Positively chargeable toner-particle of binding resin and magnetic oxide and the relation at silica and inorganic micro powder end is easily controlled at least by control.

People's discovers that the powder characteristics and the image forming course in the electrophotographic processes of the developer layer under concretion state are closely related according to the present invention.When finding especially in being applicable to the system that is easy to generate the toner deterioration because of high speed printing, be in order to obtain high reliability and the stable requisite rerum natura of picture quality.Below, the relation of the powder characteristics of the developer layer in explanation of combining image forming process and the image forming course under the concretion state.

In Fig. 1, developer pond in the roughly right half cycle face of developer carrier 102 and the developer reservoir 106 often contacts, and the developer of its developer carrier near surface is developed the magnetic force of the magnetic production part 103 in the agent supporting body and/or electrostatic force and adheres to and remain on the developer carrying surface.When developer carrier 102 was driven in rotation, the developer layer of its developer carrying surface was in the process of the position of passing through developer limiting part 104, and being put in order stratification is the uniform thin layer T1 of each several part thickness.In order to limit this bed thickness, have about 200～300 μ m relief widths as the developer limiting part 104 of the developer bed thickness limiting part that constitutes by the ferromagnetism metal according to the surface of distance developer carrier 102 and hang down with mode that developer carrier 102 is faced mutually.The magnetic line of force of magnetic pole N1 by coming from magnetic production part 103 focuses on developer limiting part 104, can form the thin layer (developer layer) of developer on developer carrier 102.As by the developer layer T1 of whole stratification, preferably keep the minimum clearance between the body (for example, photosensitive drums) 101 also thin than developer carrier among the developing regional A 102 and sub-image.The present invention to by such developer layer T1 with the developing apparatus of the mode of latent electrostatic image developing, be that the non-contact type developing apparatus is effective especially.In addition, the charged of developer mainly is to follow the rotation of developer carrier 102 that rubbing contact takes place by the developer in developer carrying surface and near the developer pond it to finish.Then, follow the rotation of developer carrier, the above-mentioned developer thin layer surface on the developer carrier 102 rotates to sub-image and keeps body 101 1 sides, and keeps body 101 and developer carrier 102 immediate positions by sub-image, that is, and and developing regional A.Pass through in the process at this, the developer of the developer thin layer of developer carrier 102 surperficial sides keeps the electric field that direct current and alternating voltage produced between body 101 and the developer carrier 102 and circles in the air by being applied to sub-image, and keeps at the sub-image of developing regional A that (gap α) moves back and forth between 102 of body 101 surfaces and the developer carriers.Finally, the developer of developer carrier 102 1 sides optionally moves on the surface that is attached to sub-image maintenance body 101 surfaces according to the current potential pattern of sub-image, forms developer successively as T2.

The developer carrying surface that has optionally consumed developer by developing regional A rotates to the developer pond of developer reservoir 106 again, thereby accept resupplying of developer, the developer thin layer T1 face of developer carrier 102 is transferred to developing regional A, carries out developing procedure repeatedly.The developer image that is developed by/or be not transferred on the transfer printing material by the intermediate transfer body, thereafter, photographic fixing in the photographic fixing operation.

In addition, in Fig. 1,, used according to the ferromagnetism metal that hangs down with mode that developer carrier 102 is faced mutually as limiting part 104, but as shown in Figure 2, also can be the structure that limiting part 104 is made elastic body and connected with developer carrier 102.

In this image forming course, the roughly right half cycle face of developer carrier 102, that is, the developer ponds in the developer reservoir 106 are used to make the developer round-robin mixing components 105 in the developer reservoir 106 constantly to stir, so are in and continue the state that is subjected to a certain degree shearing.Further, developer forms on developer carrier 102 in the process of thin layer of developer, and the magnetic line of force that comes from magnetic pole N1 focuses on limiting part 104, therefore developer can be intensive, carry out the formation of thin layer under this state, therefore, developer is subjected to very large shearing.In addition, with high speed printing, high image quality is that the policy of target is the policy that improves the policy of the rotational speed of developer carrier 102, dwindles the relief width between the surface of limiting part 104 and developer carrier 102, and the shearing that therefore puts on developer further increases.

Like this, in developer container, developer often is subjected to big shearing.As a result, the developer that the embedding etc. of the external additive that the shearing increase in the developer reservoir causes caused takes place and worsens in developer easily.When producing the developer deterioration, be easy to generate the concentration reduction that the developer carried charge reduces the durable latter half that is caused.Further, form on developer carrier in the process of thin layer of developer, because suffered shearing during by limiting part, and the fringe that causes being formed at the developer on the developer carrier becomes inhomogeneous, picture quality easily worsens, and then photographic fog also easily worsens.In addition, because suffered shearing causes that developer worsens during by limiting part, therefore easily produce concentration and reduce in durable latter half.

And then in the developing process to photoreceptor, also because the uneven fringe on the developer carrier that forms as described above, in developing regional A, the developer that exceeds needs circles in the air on the current potential pattern of sub-image, thereby causes deterioration of image.Further, because circling in the air, the developer that exceeds needs on the current potential pattern of sub-image, causes the developer exhausting amount increase easily.

Being we can say by above content, is being in the image forming course of target with high speed printing, high image quality, and the powder characteristics of the developer layer under the control concretion state is extremely important.

That is, developer of the present invention is characterized in that, the nothing constraint yield strength of this developer when primary consolidation stress 5.0kPa is 0.1～2.5kPa, and the nothing constraint yield strength of this developer when primary consolidation stress 20.0kPa is 2.5～5.5kPa.

The relation that can retrain yield strength (U) according to primary consolidation stress (X) and the nothing as feature of the present invention is discussed the easy porousness with the fixed powder layer of any load, that is the powder characteristics (aggregation force between developer particle) of tightly compacted developer layer, is discussed.Do not have the stirring in the developer reservoir brings in constraint yield strength (U) and the above-mentioned image forming course loose easy degree, shearing that developer is restricted parts and by restrictions and on developer carrier the situation of the fringe the during fringe of formation developer relevant.And, the expression of primary consolidation stress (X) among the present invention be: owing to the shearing that is subjected in developer reservoir puts on stress on the tightly compacted developer.Therefore, nothing constraint yield strength in the time of can be according to primary consolidation stress 5.0kPa is discussed the less state powder characteristics down of shearing that puts on developer, and the nothing during according to primary consolidation stress 20.0kPa retrains yield strength powder characteristics under the bigger state of the shearing that puts on developer is discussed.And, by estimating the variation of the nothing constraint yield strength between these primary consolidation stress, express the powder characteristics of the developer layer under the concretion state in the image forming course.

In addition, the invention is characterized in that the pass below primary consolidation stress 20.0kPa fastens, primary consolidation stress 20.0kPa approaches the upper limit that powder can exist with powder, if make the state that applies the above stress of 20.0kPa, then developer closely knit fully easily (packing).Therefore, for the powder characteristics of developer is discussed, preferably below primary consolidation stress 20.0kPa, discuss.

During the primary consolidation stress 5.0kPa of this developer and the nothing constraint yield strength during 20.0kPa when satisfying the scope of the present invention's regulation,, also become, can suppress the deterioration of developer as avoiding this shearing even developer is sheared in developer.Therefore, even when improving print speed, also can obtain stable image color and do not produce developer and worsen.In addition, when being formed the magnetic fringe by the developer layer under the fixed state by limiting part, the developer appropriateness of being sheared is loose and pass through limiting part, therefore can stably form uniform fringe.As a result, in developing regional A, required minimal developer is circled in the air on the current potential pattern of sub-image, therefore not only can seek from the printing initial stage until the high image quality during durable latter half can also reduce developer exhausting amount.

On the other hand, the nothing constraint yield strength of this developer when primary consolidation stress 5.0kPa greater than 2.5kPa or this developer nothing constraint yield strength when the primary consolidation stress 20.0kPa greater than what the developer of 5.5kPa was represented is: developer is difficult to loosen under concretion state, that is, be the big developer of aggregation force between particle.

When using such developer, in image forming course, can produce aforesaid problem as mentioned above.

In addition, to be 0.1～2.5kPa and the nothing constraint yield strength of this developer when primary consolidation stress 20.0kPa represent less than the developer of 2.5kPa the nothing constraint yield strength of this developer when primary consolidation stress 5.0kPa is the very little developer of aggregation force between particle.When using such developer, on the contrary can not be subjected to the shearing in the developer, but the friction force of the surface of developer carrier and developer becomes too small and causes and can't obtain fully by fricative carried charge.Therefore, produce the deterioration of development, and then produce the reduction of picture quality.And, when using such developer,, therefore when with the high speed printing being the rotational speed of purpose raising developer carrier, can see significantly in developer spraying developer because aggregation is low excessively between particle.

Further, when using such developer, because developer fluffs, the amount that causes filling in developer reservoir reduces, with respect to the printed number minimizing of developer container volume.This viewpoint from the miniaturization of developer is not preferred.

As mentioned above, by with developer in the control indexes of aggregation between the particle under the concretion state in the scope of above-mentioned relation formula, can provide the developer that satisfies high durable, highly reliable, high image quality, and developer can not worsen in long-term the use yet.

At this, the primary consolidation stress (X) of gained and nothing constraint yield strength (U) are measured by ShearScan TS-12 (production of Sci-Tec company), and ShearScan measures according to the principle of " CHARACTERIZING POWDERFLOWABILITY (2002.01.24 delivers) " middle mole-coulomb model of putting down in writing that Prof.VirendraM.Puri writes.

Particularly, use can to the straight line that the cross-wise direction straight line applies shearing force shear cell (cylindric, diameter 80mm, volume 140cm ³), room temperature environment (23 ℃ are measured under 60%RH).In this cell, add developer, apply the vertical load of 2.5kPa, making fixed powder layer makes its closeest occupied state that becomes under this vertical load (from detected pressures also can be unmanned for error ground makes this concretion state this point consideration automatically, preferably utilize the mensuration of ShearScan in the present invention.)。Fixed powder layer when similarly forming vertical load and being 5.0kPa and 10.0kPa.Then, carry out following test: the vertical load that is applied when the sample that forms under each vertical load is continued to apply the fixed powder layer of formation, slowly apply shearing force simultaneously, and measure the change of the shear stress of this moment, determine stationary point thus.Arriving stationary point is to judge like this: promptly, in above-mentioned test, the displacement that the load that the displacement of shear stress and being used to applies vertical load applies the vertical direction of parts diminishes, and when both obtain stable value, thinks to have arrived stationary point.Then, gently remove vertical load, make the failure envelope (drawing of vertical load stress vs shear stress) under each load, obtain Y intercept and slope from the fixed powder layer that arrives stationary point.Utilize in the parsing of mole-coulomb model, do not have constraint yield strength and primary consolidation stress and be expressed from the next, above-mentioned Y intercept is " aggregation force ", and slope is " internal friction angle ".

The c=aggregation force,

σ _SspThe vertical load of=stationary point)

Draw the nothing constraint yield strength and the primary consolidation stress (Flow Function Plot) that calculate under each load, based on this straight line of drawing a picture.Primary consolidation stress when obtaining nothing constraint yield strength 5.0kPa and 20.0kPa by this straight line.

In the present invention importantly: the nothing constraint yield strength of this developer when the primary consolidation stress 5.0kPa controlled to 0.1kPa～2.5kPa, and the nothing constraint yield strength during with primary consolidation stress 20.0kPa controls to 2.5kPa～5.5kPa.Its control device is not particularly limited, and for example, can control primary consolidation stress and do not have the constraint yield strength as following.

The result that people of the present invention study the composition material that is used for toner, discovery can be controlled the primary consolidation stress (X) of the Positively chargeable developer concretion state under and the relation that nothing retrains yield strength (U) by the outside proper additive of adding in having the toner-particle of for example binding resin and magnetic oxide at least.

Particularly, preferably be associated with zeta potential under the pH that the Positively chargeable toner-particle is distributed to the dispersion liquid that forms in the water and add the inorganic micro powder end as external additive, it is zeta potential below the 40mV that this inorganic powder has difference with the zeta potential of Positively chargeable toner-particle.The zeta potential of the Positively chargeable toner-particle under the so-called pH that the Positively chargeable toner-particle is distributed to the dispersion liquid that forms in the water, expression be the surface charge density of the powder of the toner-particle under this pH.Therefore, the absolute value of the so-called difference of using zeta potential is meant to use to have and the surface charge density on the toner-particle surface inorganic micro powder end of surface charge density of equal value almost as the Positively chargeable toner-particle below the 40mV and inorganic micro powder end.Usually, when in toner-particle, adding the inorganic micro powder end, can produce the such intermolecular force of Van der Waals force, electrostatic attraction, liquid bridge power etc. as everyone knows.Be controlled to be equivalence by the toner-particle that such gravitation is worked and the electric density on surface separately, inorganic micro powder end, can on the direction that relaxes the suffered gravitation in toner-particle and inorganic micro powder end, act on repulsive force, therefore can reduce aggregation force between developer particle.Thus, can easily control to as this developer of feature of the present invention nothing constraint yield strength when the primary consolidation stress 5.0kPa is that 0.1～2.5kPa and this developer nothing constraint yield strength during at primary consolidation stress 20.0kPa is 2.5～5.5kPa.

The difference of the zeta potential at Positively chargeable toner-particle and inorganic micro powder end does not produce the effect of the mitigation gravitation that relaxes above-mentioned explanation during greater than 40mV, so aggregation force becomes big between particle.Therefore, the developer that caused such as the embedding of the external additive that causes of the shearing increase in the developer generation developer reservoir worsens.As a result, the carried charge that developer takes place reduces the concentration reduction of the durable latter half that causes.Further, on developer carrier, form in the process of developer thin layer, because the fringe that suffered shearing causes being formed at the developer on the developer carrier during by limiting part becomes inhomogeneous, so deterioration of image quality, and then photographic fog also worsens.In addition, because suffered shearing also can cause developer to worsen during by limiting part, the concentration that therefore produces durable latter half reduces.

And then in the developing process to photoreceptor, because the uneven fringe on above-mentioned such developer carrier that forms, at developing regional A, the developer that exceeds needs circles in the air on the current potential pattern of sub-image, thereby causes deterioration of image.Further, because circling in the air, the developer that exceeds needs on the current potential pattern of sub-image, cause developer exhausting amount also to worsen.

The assay method of the zeta potential of measuring among the present invention is shown below.

The zeta potential at toner-particle and inorganic micro powder end is to use ultrasound wave mode zeta potential determinator DT-1200 (production of Dispersion Technology company) to measure.As dispersion liquid, prepare the 0.5vol% aqueous solution at toner-particle or inorganic micro powder end with pure water.The nonionic that zeta potential is not exerted an influence that adds as required with respect to granule density 0.4 quality % is a spreading agent.Thereafter, disperseed 3 minutes with ultrasonic dispersing machine, stirred 10 minutes on deaeration limit in limit then, makes the dispersion liquid at toner-particle or inorganic micro powder end.When measuring toner-particle, use this toner dispersion liquid, carry out the mensuration of zeta potential.At this moment, measure the pH of dispersion liquid simultaneously.When measuring the zeta potential at inorganic micro powder end, at first with 1 mol HCl aqueous solution or 1 mol KOH aqueous solution titration inorganic micro powder end dispersion liquid.Then, in the dispersion liquid at inorganic micro powder end, add the required 1 mol HCl aqueous solution or the 1 mol KOH aqueous solution of pH value of the dispersion liquid be used to adjust to toner-particle, adjust to after the pH value identical, use said apparatus to measure zeta potential with the dispersion liquid of toner-particle.

In addition, as the inorganic micro powder end, the preferred at least a kind of oxide that is selected from zinc paste, aluminium oxide, the magnesium oxide that uses, at this moment, easily the difference with the surface charge density at the surface charge density on Positively chargeable toner-particle surface and inorganic micro powder end controls to the direction that diminishes, therefore, be preferred from bringing into play the effect this point that relaxes aggregation force between toner-particle on Positively chargeable toner-particle surface effectively.

Wherein, more preferably the magnesia crystal few with lattice imperfection of sneaking into of disparate metals in order to embody the effect of mitigation aggregation force of the present invention effectively, especially preferably used, promptly highly purified fine magnesium oxide micro-powder end in the fine magnesium oxide micro-powder end.The purity at fine magnesium oxide micro-powder end can use the half breadth at the X-ray diffraction peak at fine magnesium oxide micro-powder end to estimate.

Use in the Alpha-ray X-ray diffraction of CuK, the fine magnesium oxide micro-powder end preferably Bragg angle (2 θ ± 0.2deg) there is the characteristic peak of (200) face of magnesia crystal at the 42.9deg place, and this Bragg angle (half breadth at the X-ray diffraction peak at 2 θ ± 0.2deg)=42.9deg place is below the 0.40deg.The half breadth at this X-ray diffraction peak is 0.40deg when following, represents magnesian crystallinity height, that is, the sneaking into of disparate metals, lattice imperfection etc. are few, and the unicity of magnesia crystal is strong, is highly purified.

This X ray peak half breadth is during greater than 0.40deg, and the expression crystallinity is poor, that is, the purity of magnesia crystal is low.Just, because the sneaking into of disparate metals, lattice imperfection, the demonstration that broadens of lattice deformability, X-ray diffraction peak.Under the situation at such fine magnesium oxide micro-powder end, easily produce the charged leakage that disparate metals causes, can't obtain the static focus power alleviation effects among the present invention fully.In addition, lattice imperfection causes the water tolerance variation, and the aquation that moisture absorption causes takes place, and can't obtain the effect of above-mentioned mitigation aggregation force.Simultaneously, it is inhomogeneous that shape easily becomes, and size-grade distribution broadens etc., is difficult to control rerum natura.

X-ray diffraction among the present invention is measured and is to use the CuK alpha ray to measure under the following conditions.

[specimen preparation]

1) in the 500ml beaker,, adds the methyl alcohol of 200ml with respect to the 3g developer.

2), make external additive free with ultrasonic dispersing 3 minutes.

3) at the bottom of beaker, stick magnet and catching under the state of magnetic color tuner particle, separating the methyl alcohol supernatant that comprises free external additive.

4) after the separation of supernatant, the magnetic color tuner particle in the beaker is added 200ml methyl alcohol once more, and repeats 3 times 2), 3) operation.

5) utilize the membrane filter of mesh 2 μ m, the methyl alcohol supernatant that is separated is carried out vacuum filtration and reclaims solid constituent, obtain the external additive sample.

[X-ray diffraction condition determination]

Used mensuration machine: the powerful X-ray diffraction device (RINT TTRII) of the sample water flat pattern that Rigaku Corporation produces

Fluorescent tube: Cu

The collimated beam optical system

Voltage: 50kV

Electric current: 300mA

Start angle: 30 °

Termination point: 50 °

Sampling width: 0.02 °

Sweep speed: 4.00 °/min

Divergent slit: open

Disperse perpendicular slit: 10mm

Scatter slit: open

Receive slit: 1.0mm

The analysis software " Jade6 " that uses Rigaku Corporation to produce carries out the ownership at gained X-ray diffraction peak and the calculating of half breadth.

Above-mentioned fine magnesium oxide micro-powder end is 0.5～20.0mgKOH/g at the acid number of developer, is preferably 1.0～10.0mgKOH/g, especially brings into play effect when being preferably 3.0～7.0mgKOH/g especially.

Be controlled in this scope by the acid number with developer, the compatibility on the carboxyl on Positively chargeable toner-particle surface and surface, fine magnesium oxide micro-powder end improves, and can make the fine magnesium oxide micro-powder end be present in the toner-particle surface reliably.As a result, the fine magnesium oxide micro-powder end can be controlled at only scope from the ionization rate of toner-particle, bring out the effect that relaxes the aggregation force between developer most effectively.Further, the scope by the control acid number can make the Positively chargeable on toner-particle surface more even, the result, it is more even that the Positively chargeable on developer surface also becomes, and can further relax the aggregation between developer, can obtain high meticulous image steadily in the long term.

During the acid number of developer is not enough 0.5mgKOH/g, the compatibility between toner-particle surface and the fine magnesium oxide micro-powder end reduces, and therefore is easy to generate the fine magnesium oxide micro-powder end and breaks away from from the toner-particle surface.As a result, can't obtain relaxing the effect of the aggregation force between developer.In addition, when acid number surpassed 20.0mgKOH/g, the affinity between toner-particle surface and the fine magnesium oxide micro-powder end became excessive, can't obtain relaxing the effect of the aggregation force between developer.And then, when acid number surpasses 20.0mgKOH/g, be used under the situation of Positively chargeable developer, there are the negative charging grow of the binding resin in the toner-particle, the tendency that image color reduces and photographic fog increases.

As mentioned above, when using the fine magnesium oxide micro-powder end, even in toning system at a high speed, also can obtain steadily in the long term not having the picture quality of hangover environment is not relied on, and then be difficult for producing concentration reduction, photographic fog etc.

In addition, fine magnesium oxide micro-powder end preferred volume mean grain size (Dv) is 0.1～2.0 μ m, more preferably 0.9～2.0 μ m, more preferably 1.0～1.5 μ m.In addition, the volume distributed median accumulated value with fine magnesium oxide micro-powder end of the following particle diameter of 1/2 times of particle diameter of this volume average particle size is preferably below the 10.0 volume %, more preferably below the 7.0 volume %.In addition, the volume distributed median accumulated value about the fine magnesium oxide micro-powder end of 2 times of particle diameters more than the particle diameter with this volume average particle size is preferably below the 10.0 volume %, more preferably below 7.0%.Volume average particle size less than the fine magnesium oxide micro-powder end of 0.1 μ m toner-particle is given aspect mobile unfavorable, the result, aggregation improves between the particle of developer, durable latter half concentration reduce.In addition, volume average particle size is 2.0 μ m when above, and it is free from toner-particle greatly and easily that the particle diameter at fine magnesium oxide micro-powder end becomes, and therefore can't obtain relaxing the effect of aggregation fully, so not preferred.Further, the following volume distributed median accumulated value of 1/2 times of particle diameter of this volume average particle size is that 10 volume % are above, 2 times of particle diameters of this volume average particle size are above volume distributed median accumulated value is that 10 volume % are when above, size-grade distribution broadens, therefore be easy to generate above-mentioned disadvantage, can't fully obtain relaxing the effect of the aggregation of developer.

As the means that the volume average particle size that realizes the fine magnesium oxide micro-powder end is that 1/2 times of volume distributed median accumulated value below the particle diameter of 0.1～2.0 μ m, this volume average particle size is below the 10 volume %, 2 times of volume distributed median accumulated values more than the particle diameter of this volume average particle size are size-grade distribution such below the 10 volume %, can use common grading plant, be not particularly limited.

As the determinator of the size-grade distribution at the fine magnesium oxide micro-powder end in the developer of the present invention, use laser diffraction/diffuse transmission type particle size distribution device LA-920 (HORIBA production).As assay method, in the ion exchange water of 200ml as dispersion liquid, the sample concentration that becomes about 80% according to transmissivity adds number mg sample.Then, this dispersion liquid is used ultrasonic dispersing machine dispersion treatment 1 minute, the relative index of refraction of fine magnesium oxide micro-powder end and water is set at 1.32, what utilize aforementioned determinator mensuration fine magnesium oxide micro-powder end is the size-grade distribution of benchmark with the volume, obtains the following volume distributed median accumulated value and the above volume distributed median accumulated value of 2 times of particle diameters of this volume average particle size of 1/2 times of particle diameter of volume average particle size, this volume average particle size.

In addition, the isoelectric point at the fine magnesium oxide micro-powder end in the developer of the present invention is preferably 8～14, and more preferably 9～14, be preferably 12～14 especially.The isoelectric point at fine magnesium oxide micro-powder end is lower than at 8 o'clock, and the just charged ability at fine magnesium oxide micro-powder end reduces, and the effect that therefore relaxes aggregation can reduce.In addition, because the charging property of developer becomes inhomogeneous, so photographic fog takes place easily.

Obtain the isoelectric point at fine magnesium oxide micro-powder end by zeta potential.In the present invention, use ultrasound wave mode zeta potential determinator DT-1200 (production of Dispersion Technology company) to measure the zeta potential at fine magnesium oxide micro-powder end.Make dispersion liquid with pure water, the aqueous solution of the 0.5Vol% at modulation fine magnesium oxide micro-powder end is with ultrasonic dispersing machine (Sonic﹠amp; Materials company produces VCX-750) disperseed 3 minutes after, deaeration limit, limit stir about made dispersion liquid in 10 minutes.Use said apparatus to draw the pH variation diagram of the zeta potential of this dispersion liquid, calculate isoelectric point by chart.In addition, so-called isoelectric point is that zeta potential is the value of 0 o'clock pH.

In addition, the specific surface area at employed fine magnesium oxide micro-powder end is preferably 1.0～15.0m among the present invention ²/ g.

Specific surface area is greater than 15.0m ²During/g, the fine magnesium oxide micro-powder end is embedded in the toner-particle easily, that is, easily produce developer and worsen.And then, under high humidity environment the moisture absorption quantitative change many, charged can reduce and durable latter half concentration reduce.In addition, specific surface area is less than 1.0m ²During/g, the easy generation of developer can't obtain problems such as mobile fully, that concentration is light.

As the assay method of BET specific surface area, according to BET specific surface area method, use specific area measuring device GEMINI2375 (Shimadzu Seisakusho Ltd.), make sample surfaces absorption nitrogen, use BET specific surface area multipoint method calculated specific surface area.

In addition, the MgO content among the present invention in the particle of employed fine magnesium oxide micro-powder end is preferably more than 98.00%, more preferably more than 99.90%.The content of MgO is lower than 98.00%,, when the purity of MgO is hanged down, can not fully obtain the effect of the mitigation aggregation force brought at the fine magnesium oxide micro-powder end, so not preferred that is.

In addition, from the mitigation of aggregation force between effective performance particle and the toner-particle surface exist equably the inorganic micro powder end aspect, the ionization rate at inorganic micro powder end preferably in 0.1～5.0% scope, more preferably 2.0～4.0%, be preferably 2.5～3.5% especially.Ionization rate was greater than 5.0% o'clock, and developer can't obtain suitable chargeding performance and be not preferred.And then the amount that is present in the inorganic micro powder end of toner-particle near surface reduces, and the effect that therefore relaxes aggregation force between particle reduces.

For ionization rate being controlled at suitable scope, can realize by in known outside adding method, adjusting outside adding conditional.As stirring apparatus, can use Henschel mixer, homogenizer etc., more preferably use Henschel mixer.The outside intensity of adding is regulated by the angle and the mixing time of control revolution, baffle plate, also needs to take into full account the ionization rate of controlling the inorganic micro powder end with the interaction of other external additive.

In the present invention, measure the ionization rate of inorganic micro powder end by grain analyser (PT1000: Yokogawa Motor (strain) is produced) from toner-particle.Grain analyser is a kind ofly particulates such as toner are imported in the plasma singly and to know element, the granule number of shiner, the device of grain diameter according to the luminescent spectrum of particulate, measures by the principle of the 65th～68 page of record of JapanHardcopy97 collection of thesis.Particularly, the toner sample placed under the environment of 23 ℃ of temperature, humidity 60% carry out damping an evening, at the toner sample that uses under the above-mentioned environment after the helium that contains 0.1% oxygen is measured this damping.Promptly, measure carbon atom (measuring wavelength 247.86nm), measure aluminium atom (measuring wavelength 396.15nm) with passage 1 with passage 3, according to the luminous number of carbon atom of 1 scanning is that 1000～1400 mode is taken a sample, the luminous several sums that scan repeatedly up to carbon atom reach more than 10000, the luminous number of accumulative total.Then, the luminous number of counting only aluminium atom at this moment is as the number of free alumina.In addition, Ci Shi noise eliminating level is 1.50V.Then, the viewpoint with regard to ionization rate describes.For example, consider to import under the situation in the plasma, in the time of in importing to plasma, can observe as the luminous of the carbon of binding resin component respectively and come from aluminium atom luminous of aluminium oxide adding the toner-particle of aluminium oxide as the inorganic micro powder end.At this moment, think simultaneously luminous atom at 2.6msec with interior luminous aluminium atom from the luminous beginning of carbon atom, independent luminous of aluminium atom thought in the aluminium atom that it is later luminous.The luminous aluminium oxide that means is attached to the toner-particle surface simultaneously for carbon atom and aluminium atom, and the aluminium atom is luminous separately to mean that aluminium oxide is free from toner-particle.

Further, last its content of described inorganic micro powder is preferably 0.01～2.0 quality % of all developers.When surpassing 2.0 quality %, developer can't obtain suitable chargeding performance, and the effect that relaxes aggregation force between particle reduces.

In addition, the inorganic micro powder end can implement to use after the surface treatment with known treating agent.

In addition, in developer of the present invention,, preferably add the inorganic micro powder end, further,, more preferably add the silica micropowder in order to improve charged stability, development, flowability, permanance in order to relax aggregation between particle.In addition, clear and definite, by giving mobile ability height and the little silica micropowder and the inorganic micro powder end of number average particle diameter of primary particle used simultaneously, the inorganic micro powder end can be evenly dispersed in the toner-particle surface thus to the toner-particle surface.When the inorganic micro powder end did not evenly disperse, to the alleviation effects generation deviation of aggregation force between particle, developer worsened easily to the deterioration condition of high speed printing.As a result, the carried charge that produces developer reduces the concentration reduction of the durable latter half that is caused.And then, on developer carrier, form in the process of thin layer of developer, because the fringe that suffered shearing causes being formed on the developer on the developer carrier during by limiting part becomes inhomogeneous, so deterioration of image quality, and then photographic fog also worsens.In addition, because suffered shearing causes that developer worsens during by limiting part, the concentration that therefore produces durable latter half reduces.As the silica micropowder, preferred BET specific surface area is 70～130m ²/ g.

Further, when inorganic micro powder end did not evenly disperse, in the developing process to photoreceptor, because the uneven fringe on the developer carrier, at developing regional A, the developer that exceeds needs circled in the air on the current potential pattern of sub-image, thereby causes deterioration of image.And then on the current potential pattern of sub-image, developer exhausting amount also worsens because the developer that exceeds needs circles in the air.

As the silica micropowder, can use the what is called that the vapor phase oxidation generated by silicon halide to be called as the dry type silica of dry process or fumed silica and the so-called wet type silica made by water glass etc. the two.In addition, preferred dry silica, the few and Na of silanol group that is present in surface and silica micropowder inside of dry type silica ₂O, SO ₃ ^-Residue is few Deng making.In the dry type silica,, can obtain the composite micro-powder end of silica micropowder and other metal oxide in addition by in manufacturing process, for example other metal halide such as aluminum chloride, titanium chloride being used with halogenated silicon compound.So-called silica micropowder among the application also comprises these composite micro-powder ends.

In addition, in the present invention, the silica micropowder is preferably handled by hydrophobization.Handle by the silica micropowder being carried out hydrophobization, can prevent the reduction of the charging property of silica micropowder under high humidity environment, improve the environmental stability of frictional electrification amount that surface attachment has the toner-particle of silica micropowder.As a result, can further improve the environmental stability of developing properties such as image color as developer, photographic fog.In the present invention, when measuring the silica micropowder to the wettability of methanol mixed solvent with the transmissivity of 780nm wavelength light, the preferred transmission rate is that 80% o'clock methanol concentration is in the scope of 65～80 volume %.

Transmissivity is 80% o'clock a methanol concentration when surpassing 80 volume %, the toner that is contained charging and not preferred easily.In addition, transmissivity is 80% o'clock a methanol concentration when being lower than 65 volume %, is vulnerable to the influence of airborne moisture, is difficult to obtain the good development as toner.

In the present invention, the relation of described transmissivity and methanol concentration, i.e. the wettability of silica micropowder, the hydrophobic property of silica micropowder just are to use methyl alcohol to drip that transmittance graph measures.Particularly,, can enumerate for example Rhesca Co. as its determinator, Ltd. company produce powder wettability testing machine WET-100P, concrete measurement operation can list following illustrative method.

At first, in container, add the aqueous methanol liquid that 70ml is made of 60 volume % methyl alcohol and 40 volume % water,, disperseed 5 minutes with ultrasonic disperser in order to remove bubble in its test sample etc.Accurately weighing 0.5g adds to wherein as the silica of analyte, and preparation is used to measure the sample liquid of the hydrophobic property of developer.

Then, the limit is with 6.67s ^-1Speed stir this test sample liquid, methyl alcohol is added continuously with the rate of addition of 1.3ml/min. in the limit, with the light measurement transmissivity of wavelength 780nm, makes methyl alcohol and drips transmittance graph.In addition, in this is measured,, use the flask of glass of circle, the thickness 1.75mm of diameter 5cm,, use the spindle of length 25mm, maximum gauge 8mm and applied the magnetic stirrer of fluor resin coating as magnetic stirrer as flask.

As the treating agent that hydrophobization is handled, can use or use simultaneously the treating agent as silicon varnish, various modified silicone resin varnish, unmodified silicone oil, various modified silicon oil, silane compound, silane coupling agent and organo-silicon compound, organic titanic compound so separately.Wherein, consider, preferably handle with silane compound, the silicone oil of the substituting group with nitrogenous element (particularly amino) from the charging property aspect.

Wherein, having amino silane compound subtend silica provides the contribution of Positively chargeable big, treatment capacity for a long time, Positively chargeable grow, but because amino water wettability makes the hydroscopicity increase.Therefore, when using silane compound, preferably use silicone oil to handle simultaneously.In addition, processing can be carried out according to known method.

In addition, in order to make the developer that satisfies primary consolidation stress of the present invention and do not have the relation of constraint yield strength, preferably developer what pass through that Coulter counter measures with the 256G passage is in the size-grade distribution of benchmark with the number, the relation of peak granularity X and half breadth Y satisfies following formula:

2.06×X-9.0≤Y≤2.06×X-7.5

In addition, peak granularity X is the central value of the passage of frequency maximum, and half breadth Y is central value poor of 2 passages that comprises half frequency of maximum frequency.

What measure with the 256G passage by Coulter counter is in the size-grade distribution of benchmark with the number, half breadth Y is Y to the pass of peak granularity X〉during 2.06 * X-7.5, mean this developer be the accumulation number of other granularity more than the accumulation number of peak granularity X, be the wide developer of size-grade distribution.Under the situation of such developer, exist the charged distribution of developer to produce the tendency that aggregation uprises between deviation and particle.As a result, the developer that the embedding of the external additive that the shearing increase in the developer reservoir causes etc. caused takes place developer easily worsens, and easily produces concentration in durable back and reduces.Further, on developer carrier, form in the process of thin layer of developer, because the fringe that suffered shearing causes being formed at the developer on the developer carrier during by limiting part easily becomes inhomogeneous, picture quality reduces, and then also has the tendency that is easy to generate photographic fog.In addition, because suffered shearing and developer easily takes place worsen during by limiting part easily produces concentration in durable back and reduces.

Further, because the uneven fringe on the developer carrier, at developing regional A, the developer that exceeds needs circles in the air on the current potential pattern of sub-image, thereby cause that picture quality reduces, further, because circling in the air, the developer that exceeds needs on the current potential pattern of sub-image, causes the developer exhausting amount increase.In addition, what measure with the 256G passage by Coulter counter is in the size-grade distribution of benchmark with the number, when half breadth Y is Y＜2.06 * X-9.0 to the pass of peak granularity X, means that the size-grade distribution of this developer is very narrow.The developer of narrow particle size distribution is charged evenly, so aggregation reduces between particle, and when using such developer, the shearing in the developer dies down.But the surface of developer carrier and the friction force of developer become too small, therefore are difficult to fully obtain by fricative carried charge.Thereby, produce the deterioration of development, and then also be easy to generate the reduction of picture quality.In addition, when using such developer,, when improving the rotational speed of developer carrier for high speed printing, be easy to generate developer and in developer, spray because aggregation is low excessively between particle.

Further, in the situation of the developer that obtains narrow particle size distribution,, then can make the developer of narrow particle size distribution if in the classification operation, significantly remove micro mist opisthosoma and coarse dispersion, but have the yield step-down of toner-particle of the size-grade distribution of expectation, unrealistic in the manufacturing.

Further, developer preferred acid number of the present invention is 0.5～20.0mgKOH/g, 1.0～10.0mgKOH/g more preferably, preferred especially 3.0～7.0mgKOH/g.Be controlled at this scope by acid number, can improve the carboxyl on Positively chargeable toner-particle surface and the compatibility on surface, inorganic micro powder end, make the inorganic micro powder end be present in the toner-particle surface reliably developer.As a result, embody the repulsive force that is used to relax aggregation force between developer particle effectively, the loose easy degree of developer under concretion state improves.During the acid number of developer is not enough 0.5mgKOH/g, the compatibility between toner-particle surface and the inorganic micro powder end reduces, and therefore easily produces the phenomenon that the inorganic micro powder end breaks away from from the toner-particle surface.As a result, the effect that relaxes aggregation force between particle reduces, and the loose easy degree of the developer under the concretion state worsens.In addition, when acid number surpassed 20.0mgKOH/g, the affinity between toner-particle surface and the inorganic micro powder end became excessive, and the effect that relaxes aggregation force between particle diminishes.Further, when acid number surpasses 20.0mgKOH/g, under the situation that is applicable to the Positively chargeable toner, there are the negative charging grow of the binding resin in the toner-particle, the tendency that image color reduces, photographic fog increases.

In addition, the insoluble one-tenth component of tetrahydrofuran (THF) of the binding resin composition of the preferred Soxhlet extractron of developer of the present invention in the time of 16 hours is 0.1～50.0 quality %.More preferably 10.0～50.0 quality %, more preferably 20.0～50.0 quality %.

The insoluble composition of THF has the effect of the endurance strength of keeping developer, prevents that developer from worsening (embedding of external additive etc.) is important when being applied to high speed machines.Further, because the insoluble composition of THF is the effective constituent that is used to embody from the good release property of heater blocks such as fixing roller, when therefore being applicable to high speed machines, having and reduce the effect of developer the adhesion amount of heater blocks such as fixing roller.When surpassing 50.0 quality %, not only fixation performance worsens, and has raw-material dispersed the deterioration and the uneven tendency of charging property in the developer, causes aggregation force deterioration between developer particle.

In addition, the insoluble composition of the preferred THF of developer of the present invention in the zone of molecular weight 3000～30000 main peak is arranged, and the peak area of molecular weight below 100,000 is 70～100 quality % with respect to all peak areas in the molecular weight distribution of measuring by GPC.

By zone main peak is arranged, raw-material dispersed the change well in the developer at molecular weight 3000～30000.As a result, charging property is even, and aggregation force is relaxed between developer particle.And then main peak is arranged by zone at molecular weight 3000～30000, can obtain good low-temperature fixing and anti-obstruction.And then, because the excellent in te pins of durability of the developer during high speed printing worsens so developer does not take place.During main peak molecular weight less than 3000, not only anti-obstruction deterioration, the developer when also producing high speed printing worsens, and can see that image color reduces, picture quality reduces.The main peak molecular weight surpasses at 30000 o'clock, can't obtain sufficient fixation performance.Further, when making toner-particle, raw-material dispersed the deterioration chargedly becomes inhomogeneous, and aggregation force worsens between developer particle.In addition, the peak area of molecular weight below 100,000 can't obtain sufficient fixation performance during with respect to all peak area less thaies 70%.

As the kind of binding resin among the present invention, can list polystyrene homopolymerization resin, polystyrene copolymer resins, vibrin, polyol resin, Corvic, phenolics, natural modified phenolics, natural resin modification maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, urethane resin, polyamide, furane resin, epoxy resin, xylene resin, polyvinyl butyral, terpene resin, coumarone-indene resin, petroleum line resin.

From the aspect that is used for the Positively chargeable toner-particle, can easily control with the aspect of the compatibility at inorganic micro powder end and consider that binding resin of the present invention is preferably the polystyrene copolymer resins.And then the polystyrene copolymer resins can be for containing carboxy resin and the potpourri or the reactant that contain the glycidyl resin.

For the comonomer of styrene monomer, can list styrene derivative, in the polystyrene copolymer resins as vinyltoluene; Acrylic acid; Acrylate is as methyl acrylate, ethyl acrylate, butyl acrylate, acrylic acid dodecane ester, 2-ethyl hexyl acrylate, acrylic acid 2-ethyl monooctyl ester, phenyl acrylate; Methacrylic acid; Methacrylate is as methyl methacrylate, Jia Jibingxisuanyizhi, butyl methacrylate, 2-Propenoic acid, 2-methyl-, octyl ester; Maleic acid; Dicarboxylic ester with two keys is as maleic acid butyl ester, maleic acid methyl esters, dimethyl maleate; Acrylamide; Vinyl cyanide; Methacrylonitrile; Butadiene; Vinyl chloride; Vinyl acetate is as vinyl acetate, vinyl benzoate; Ethene is alkene, as ethene, propylene, butylene; Vinyl ketone is as ethenyl methyl ketone, vinyl hexyl ketone; Vinyl ether is as methoxy ethylene, ethyl vinyl ether, VINYL ISOBUTYL ETHER.These ethene base system monomers can use separately or use more than 2.

Binding resin among the present invention preferably has the acid number of 0.5～20.0mgKOH/g scope.Be preferably the resin of acid number especially with 0.5～15.0mgKOH/g.If greater than 20.0mgKOH/g, when then being applied to the Positively chargeable toner, the negative charging grow of the binding resin in the toner-particle, if less than 0.5mgKOH/g, then the compatibility between toner-particle surface and the inorganic micro powder end reduces, and therefore easily produces the inorganic micro powder end and breaks away from from the toner-particle surface.As a result, the alleviation effects to aggregation force between particle reduces the loose easy degree deterioration of the developer under the concretion state.

As the monomer of the acid number of adjusting binding resin, for example can list acrylic acid such as acrylic acid, methacrylic acid, acrylic acid α-ethyl ester, crotonic acid, cinnamic acid, vinyl acetic acid, iso-crotonic acid, angelic acid and α thereof-or β-alkyl derivative; Unsaturated dicarboxylic and monoesters or acid anhydrides etc. such as fumaric acid, maleic acid, citraconic acid, alkenyl succinic, itaconic acid, mesaconic acid, dimethyl maleic acid, dimethyl fumarate.Wherein, particularly from the control acid number, preferably use the monoester derivates of unsaturated dicarboxylic.

Particularly preferred compound for example can list, such α such as monomethyl maleate, ethyl maleate, the positive butyl ester of maleic acid list, maleic acid list n-octyl, maleic acid monoene propyl ester, phenyl ester maleate, monomethyl fumarate, monomethyl ester, the positive butyl ester of fumaric acid list, fumaric acid monophenyl, the monoesters class of β-unsaturated dicarboxylic; The monoesters class of the alkenyl dicarboxylic acid that the positive butyl ester of n-butene base mono succinate, positive ocentyl succinic mono-methyl, n-butene propylmalonic acid mono ethyl ester, positive dodecenyl succinic monomethyl glutarate, the positive butyl ester of n-butene base hexane diacid list etc. are such etc.

Whole monomers with respect to 100 mass parts formation binding resin can add the above-mentioned carboxylic monomer that contains of 0.1～20.0 mass parts, preferably add 0.2～15.0 mass parts.

As the synthetic method of binding resin, can list solution polymerization process, emulsion polymerization, suspension polymerization.

Wherein, emulsion polymerization be with emulsifying agent will be almost water-fast monomer (monomer) be dispersed in aqueous phase with fine granularity, use water miscible polymerization initiator to carry out the method for polymerization.In the method, easy conditioned reaction heat, phase (oil phase that is made of polymkeric substance and monomer) and water that polymerization takes place separate, so cessation reaction speed is little, and polymerization rate is big as a result, can obtain the material of high polymerization degree.Further, because polymerization process is fairly simple and polymerizate is a subparticle, therefore in the manufacturing of toner, from colorant and charge control agent and reasons such as easy and other additives mixed, as the favourable aspect of the manufacture method of binder resin for toner.

But because the cause of having added emulsifying agent, it is impure that the polymkeric substance that generates easily becomes, operation such as when the taking-up polymkeric substance, need saltout, and for fear of this inconvenience, suspension polymerization is suitable.

In suspension polymerization,, can carry out polymerization with following (being preferably 10～90 mass parts) monomer of 100 mass parts with respect to 100 mass parts water solvents.As spendable spreading agent, can use polyvinyl alcohol (PVA), the partly-hydrolysed thing of polyvinyl alcohol (PVA), calcium phosphate etc., can use 0.05～1 mass parts spreading agent with respect to 100 mass parts water solvents usually.Polymerization temperature is suitable for 50～95 ℃, can suitably select according to employed initiating agent, subject polymer.

Employed binding resin preferably uses the such multi-functional polymerization initiator of following illustration to synthesize among the present invention.

Object lesson as multi-functional polymerization initiator with polyfunctional structure, can be selected from: 1,1-two-tert-butyl peroxide-3,3, the 5-trimethyl-cyclohexane, 1,3-pair-(tert-butyl peroxide isopropyl) benzene, 2,5-dimethyl-2,5-(tert-butyl peroxide) hexane, 2,5-dimethyl-2,5-two-(tert-butyl peroxide) hexane, three-(tert-butyl peroxide) triazines, 1,1-two-tert-butyl peroxide cyclohexane, 2,2-two-tert-butyl peroxide butane, 4,4-two-tert-butyl peroxide n-butyl pentanoate, two-tert-butyl peroxide, six hydrogen terephthalate, two-tert-butyl peroxide azelate, two-tert-butyl peroxide trimethyladipic acid ester, 2,2-two-(4,4-two-tert-butyl peroxide cyclohexyl) propane, 2, have 2 above peroxidating groups etc. in 1 molecule such as 2-tert-butyl peroxide octane and various polyperoxides and possess the multi-functional polymerization initiator that polymerization causes the functional group of function, and peroxidating diallyl two carbonic esters, the tert-butyl peroxide maleic acid, having peroxidating group etc. in 1 molecules such as tert-butyl peroxide allyl carbonate and tert-butyl peroxide isopropyl fumarate possesses polymerization and causes the functional group of function and the multi-functional polymerization initiator of polymerism unsaturated group.

In the middle of these, more preferably 1,1-two-tert-butyl peroxide-3,3,5-trimethyl-cyclohexane, 1,1-two-tert-butyl peroxide cyclohexane, two-tert-butyl peroxide, six hydrogen terephthalate, two-tert-butyl peroxide azelate and 2,2-pair-(4,4-two-tert-butyl peroxide cyclohexyl) propane and tert-butyl peroxide allyl carbonate.

In order to satisfy as the desired various performances of binding resin, these multi-functional polymerization initiators preferably use simultaneously with the simple function polymerization initiator.Especially preferably use ten hours half life temperatures to be lower than the polymerization initiator of this multi-functional polymerization initiator simultaneously.

Particularly, can list benzoyl peroxide, 1,1-two (tert-butyl peroxide)-3,3,5-trimethyl-cyclohexane, normal-butyl-4,4-two (tert-butyl peroxide) valerate, cumyl peroxide, α, organic peroxides such as α '-two (tert-butyl peroxide diisopropyl) benzene, tert-butyl peroxide cumene, two-tert-butyl peroxide, azo such as azoisobutyronitrile, diazoamino azobenzene and diazo-compounds etc.

These simple function polymerization initiators can add in the monomer with described multi-functional polymerization initiator simultaneously, but, preferably in polymerization process, after the half life period that multi-functional polymerization initiator through this shows, add in order to guarantee the suitable efficient of this multi-functional polymerization initiator.

From the efficient aspect, preferably use these polymerization initiators of 0.05～2 mass parts with respect to 100 mass parts monomers.

Binding resin preferably is crosslinked by cross-linkable monomer.

As cross-linkable monomer, the main monomer that uses with 2 above polymerizable double bonds.As object lesson, can list divinyl aromatic compound (for example, divinylbenzene, divinyl naphthalene etc.); The diacrylate compounds that links with alkyl chain (for example, glycol diacrylate, 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6 hexanediol diacrylate, neopentylglycol diacrylate and the material that the acrylate of above compound is replaced with methacrylate); The diacrylate compounds that links with the alkyl chain that comprises ehter bond (for example, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyglycol #400 diacrylate, polyglycol #600 diacrylate, propylene glycol diacrylate and the material that the acrylate of above compound replaced with methacrylate); The diacrylate compounds that links with the chain that comprises aromatic group and ehter bond (for example, polyoxyethylene (2)-2, two (4-hydroxyphenyl) the propane diacrylates of 2-, polyoxyethylene (4)-2, two (4-hydroxyphenyl) propane diacrylates of 2-and the material that the acrylate of above compound is replaced with methacrylate); And, polyester-type diacrylate compounds (for example, trade name MANDA (Japanese chemical drug)).As polyfunctional crosslinking chemical, the material that can enumerate pentaerythritol acrylate, trimethylolethane trimethacrylate acrylate, trimethylolpropane triacrylate, tetra methylol propane triacrylate, tetramethylol methane tetraacrylate, oligoester acrylate and the acrylate of above compound be replaced with methacrylate; Triallyl cyanurate, triallyl trimellitate; Deng.

These crosslinking chemicals preferably use 0.00001～1 mass parts, are preferably the scope of 0.001～0.05 mass parts with respect to other monomer component of 100 mass parts.

In these cross-linkable monomers, as the monomer of considering from the fixation performance of toner, anti-tack aspect to be fit to use, the diacrylate compounds that can list divinyl aromatic compound (particularly divinylbenzene), link with the chain that comprises aromatic group and ehter bond.

As other synthetic method of binding resin, can use bulk polymerization, solution polymerization process.But in mass polymerization, the end of boost reaction rate by high temperature polymerization can obtain low-molecular-weight polymkeric substance, but has the problem that is difficult to control reaction.This point, in solution polymerization process, the difference of the chain transfer of the free radical that brings by solvent and adjust initiating agent, temperature of reaction can easily obtain the polymkeric substance of desired molecular weight under the condition of gentleness, therefore preferred.Particularly, from the initiating agent use amount is suppressed to Min., do one's utmost to suppress initiating agent residual cause influence these aspects, the solution polymerization process under the also preferred pressurized conditions.

When using vibrin, can use following sour composition and pure composition as monomer as binding resin.

As 2 yuan of pure compositions, can list ethylene glycol, propylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 2,3-butylene glycol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, hydrogenated bisphenol A and (E) represented bis-phenol and the derivant thereof of formula;

[Chemical formula 1]

(R is ethene or propenyl in the formula, and x, y are respectively the integer more than 0, and the mean value of x+y is 0～10.)

And (F) glycols shown in the formula;

[Chemical formula 2]

(in the formula, R ' is-CH ₂CH ₂-or Or

X ', Y ' are respectively the integer more than 0, and the mean value of X '+Y ' is 0～10.)

As 2 yuan of sour compositions, can list omega-dicarboxylic acids and derivant thereof, for example benzene dicarboxylic acid class such as phthalic acid, terephthalic acid (TPA), isophathalic acid, phthalic anhydride or its acid anhydrides, lower alkyl esters; Alkyl dicarboxylic aid's classes such as succinic acid, hexane diacid, decanedioic acid, azelaic acid or its acid anhydrides, lower alkyl esters; Alkenyl succinic class such as positive dodecenyl succinic succinic acid, dodecyl succinic acid or alkyl succinic acid class or its acid anhydrides, lower alkyl esters; Unsaturated dicarboxylic classes such as fumaric acid, maleic acid, citraconic acid, itaconic acid or its acid anhydrides, lower alkyl esters; Deng.

In addition, preferably will play the pure composition more than 3 yuan of crosslinked composition effect and more than 3 yuan sour composition use simultaneously.

As the polyol component more than 3 yuan, can list for example D-sorbite, 1,2,3, the own tetrol of 6-, 1,4-sorbitan, pentaerythrite, dipentaerythritol, tripentaerythritol, 1,2,4-butantriol, 1,2,5-penta triol, glycerine, 2-methyl-prop triol, 2-methyl isophthalic acid, 2,4-butantriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxy benzene etc.

In addition, polybasic carboxylic acid composition as more than the ternary among the present invention can list polybasic carboxylic acid class and derivant thereof, for example trimellitic acid, pyromellitic acid, 1,2,4-benzene tricarbonic acid, 1,2,5-benzene tricarbonic acid, 2,5,7-naphthalene tricarboxylic acids, 1,2,4-naphthalene tricarboxylic acids, 1,2,4-fourth tricarboxylic acids, 1,2, the own tricarboxylic acids of 5-, 1,3-dicarboxyl-2-methyl-2-methylene carboxyl propane, four (methylene carboxyl) methane, 1,2,7,8-octane tetrabasic carboxylic acid, the acid of EnPol tripolymer and these acid anhydrides, lower alkyl esters; Tetrabasic carboxylic acid that following formula is represented etc. and these acid anhydrides, lower alkyl esters etc.

[chemical formula 3]

(X is that carbon number with 1 above carbon number side chain more than 3 is 5～30 alkylidene or alkylene group in the formula)

Employed pure composition is preferably 40～60mol%, is preferably 45～55mol% among the present invention, and sour composition is preferably 60～40mol%, is preferably 55～45mol%.In addition, the above polynary composition of ternary is preferably 5～60mol% in whole compositions.

This vibrin also obtains by common known polycondensation.

Below, the assay method of rerum natura involved in the present invention is shown.

[mensuration of the insoluble composition of THF]

The about 1.0g of weighing (W1g) resin is put into cylindrical filter paper (for example, No.86R size 28 * 100mm Japan filter paper company produces), installs to Soxhlet's extractor, uses 200ml THF as solvent, extracts 16 hours.At this moment, the return velocity with about 4 minutes～5 minutes circulation primary of the extraction cycle of solvent extracts.After extraction finishes, take out cylindrical filter paper, 40 ℃ of vacuum drying 8 hours, weighing extraction residue (W2g).Then obtain the weight (W3g) of the residual ash content of calcination in the toner.The residual ash content of calcination is obtained in the following order.Accurately adding about 2g sample and accurately weighing in the 30ml magnetic crucible of weighing in advance, then, obtain the quality that sample is a toner (Wag) by the quality that deducts crucible.Crucible is put into electric furnace in about 900 ℃ of down about 3 hours of heating, natural cooling and natural cooling more than 1 hour in exsiccator, the accurately quality of weighing crucible at normal temperatures in electric furnace.From deducting the quality of crucible here, thereby obtain the residual ash content of calcination (Wbg).

(Wb/Wa) * the residual ash content containing ratio of 100=calcination (quality %)

Can obtain the quality (W3g) of the residual ash content of calcination the sample W1g from this containing ratio.

The insoluble composition of THF is obtained by following formula.

The insoluble composition of THF (quality %)={ (W2-W3)/(W1-W3) } * 100

In addition, the mensuration of the insoluble composition of THF that does not comprise the sample of the composition beyond the resin such as binding resin is that the resin of weighing ormal weight (W1g) is obtained extraction residue (W2g) according to operation same as described above, is obtained by following formula.

The insoluble composition of THF (quality %)=(W2/W1) * 100

[distributing] by the GPC determining molecular weight

In 40 ℃ heating chamber, make post stable, feed THF with the flow velocity of per minute 1ml in the post under this temperature, inject about 100 μ l THF sample solutions and measure as solvent.In the molecular weight determination of sample, calculate the molecular weight distribution that sample has by the logarithm value of the typical curve that utilizes several monodisperse polystyrene standard models to set up and the relation of instrumentation value.Set up the polystyrene standard sample of usefulness as typical curve, use that for example TOSOH company produces or molecular weight clear and that electrician company produces is 10 ²～10 ⁷About standard specimen, it is suitable using the polystyrene standard sample about at least ten points.In addition, detecting device uses RI (refractive index) detecting device.And, as post, commercially available many combinations of Aquapak A-440 post can be able to be enumerated the combination of for example clear and shodex GPC KF-801,802,803,804,805,806,807,800P that electrician company produces, the TSKgel G1000H (H that TOSOH company produces _XL), G2000H (H _XL), G3000H (H _XL), G4000H (H _XL), G5000H (H _XL), G6000H (H _XL), G7000H (H _XL), the combination of TSK guard column.

In addition, sample is following making.

With sample join among the THF place a few hours after, fully vibration and fully mix (aggregation up to sample disappears) with THF is left standstill more than 12 hours again.Be more than 24 hours the standing time of this moment in THF.Make it pass through sample preparation filtrator (aperture 0.2～0.5 μ m can use for example Myshori Disk H-25-2 (TOSOH company production) etc.) and as the sample of GPC thereafter.In addition, to be adjusted to resinous principle be 0.5～5.0mg/ml to sample concentration.

[mensuration of acid number]

Basic operation is carried out according to JISK-0070.

1) accurate weighing 0.5～2.0g sample is as the quality W (g) of sample.

2) in the 300ml beaker, put into sample, add the mixed liquor 150ml of toluene/ethanol (4/1), dissolving.

3) methanol solution of the KOH of use 0.1 mol, with the titration of potential difference (PD) titration apparatus (for example, can utilize automatic titration, potential difference (PD) titration apparatus AT-400 (win workstation) and the electronic buret of ABP-410 that it uses capital of a country Electronics Co., Ltd to produce.)

4) use amount of Ci Shi KOH solution is as S (ml), and the use amount of measuring blank and KOH solution that will this moment is as B (ml).

5) calculate acid number by following formula.F is the factor of KOH.

Acid number (mgKOH/g)=(S-B) * f * 5.61}/W

In addition, when using developer, obtain the residual ash content of calcination, will deduct the numerical value of quality of the residual ash content of calcination as the quality of sample with the same operation of the mensuration of the insoluble composition of THF as sample.

[size-grade distribution of developer]

The size-grade distribution of developer can be measured by the whole bag of tricks, in the present invention, uses Coulter counter to carry out.Determinator uses CoulterMultisizer IIE (production of Coulter company).Electrolytic solution uses 1 grade sodium chloride, modulates about 1%NaCl aqueous solution.Can use for example ISOTON (R)-II (CoulterScientific Japan, Ltd. produces).As assay method, in the described electrolytic aqueous solution of 100～150ml, add 0.1～5.0ml surfactant (being preferably alkyl benzene sulfonate) as spreading agent, add 2～20mg working sample again.The electrolytic solution that is suspended with sample carries out about 1～3 minute dispersion treatment with ultrasonic disperser, and by described determinator, 100 μ m apertures are used in the aperture, measures volume, the number of toner-particle, calculates volume distributed median and number and distributes.At this moment, the data of being measured obtain with the form that particle diameter 1.59～64.0 μ m is divided into the passage of 256 parts.Use this with the data that 256 passages obtain, the micropowder number (4.00 μ m are following) of obtaining weight average particle diameter (D4) (with the median of each passage typical value), number average particle diameter (D1) and the meal amount of obtaining by volume distributed median (more than the 10.1 μ m), distributing and obtain by number as every passage.

[in the number size-grade distribution of developer with respect to peak granularity X half breadth Y]

Frequency A (number %) when the size-grade distribution (with reference to Fig. 4) of the 256G passage of gained calculates peak granularity X from the Coulter MultisizerIIE (production of Coulter company) that measures the size-grade distribution of above-mentioned developer.

When the frequency of peak granularity X is made as A, calculates frequency from size-grade distribution and get half value (that is, granularity A/2) is made as X1, X2 from small particle diameter one side with them.

Can obtain half breadth this moment with half breadth Y=X2-X1.

In developer of the present invention,, preferably contain following wax class in order to provide release property to developer.Employed wax has following material among the present invention.For example can list, aliphatics hydrocarbon system wax is as low molecular weight polyethylene, low-molecular-weight polypropylene, polyolefin copolymer, polyolefin-wax, microcrystalline wax, paraffin, f-t synthetic wax; The oxide of aliphatics hydrocarbon system wax is as oxidized polyethlene wax; Perhaps, their segmented copolymer; Department of botany's wax is as candelila wax, Brazil wax, vegetable wax, Jojoba wax; Animal is a wax, as beeswax, sheep oil, spermaceti; Mineral are wax, as ceresine, ceresin, paraffin oil; With the fatty acid ester is the wax class of major component, as montanic acid ester type waxes, castor wax; The wax that the part or all of deoxidation of fatty acid ester is obtained is as the deoxidation Brazil wax.Further can list as palmitic acid, stearic acid, montanic acid or have saturated straight chain the chain alkyl carboxylic acid of the alkyl of long-chain more; Unsaturated fatty acid as brassidic acid, eleostearic acid, parinaric acid; As stearyl alcohol, arachidic alcohol, docosyl alcohol, tetracosanol, ceryl alcohol, melissyl alcohol or have saturated alcohols the long-chain alkyl alcohol of the alkyl of long-chain more; Polyvalent alcohol as D-sorbite; Aliphatic amide as linoleic acid acid amides, oleamide, lauramide; Saturated fatty acid bisamide as methylene bis stearmide, the two decyl amide of ethylene, the bimonthly osmanthus of ethylene acid amides, hexamethylene bis-stearamides; As the two oleamides of ethylene, the two oleamides of hexamethylene, N, N '-two oil base adipamide, N, the such unsaturated fatty acid amide-type of N '-two oil base decanedioyl amine; As m-xylene bis-stearamides, N, the fragrant family bisamide that N '-distearyl isophathalic acid acid amides is such; Fatty acid metal salts as calcium stearate, calcium laurate, zinc stearate, dolomol (being commonly called metallic soap); Aliphatics hydrocarbon system wax is used the ethene base system monomer as styrene, acrylic acid and wax that grafting obtains; The fatty acid as mountain Yu acid monoglyceride and the partial esterification thing of polyvalent alcohol; By the resulting methyl-esterified compound of hydrogenated vegetable grease with hydroxyl.

As the wax of preferred use, can list the polyolefin that under high pressure alkene free radical polymerization is obtained; The polyolefin that resulting low molecular weight by-products is purified and obtained during to the high molecular polyolefine polymerization; The polyolefin that under low pressure uses the polymerization catalyst as Zeigler catalyst, metallocene catalyst to obtain; Utilize radioactive ray, electromagnetic wave or light to carry out the polyolefin that polymerization obtains; The low-molecular-weight polyolefin that the pyrolysis of polyphosphazene polymer alkene is obtained; Paraffin, microcrystalline wax; By synthetic synthetic chloroflo (for example, f-t synthetic wax) such as Arge method, synthol process, iron catalyst fluidized bed (Hydrocol) method; With carbon number be 1 compound as the synthetic wax of monomer, have the hydrocarbon system wax of the functional group as hydroxyl or carboxyl; Hydrocarbon system wax and potpourri with wax of functional group; With these waxes as mother metal, the wax that styrene, maleate, acrylate, methacrylate, the such vinyl monomer-grafted modification of maleic anhydride are obtained.

In addition, the preferred use by squeezing diaphoresis, solvent method, recrystallization method, vacuum distillation method, supercritical gas extraction method or fusion liquid crystal Method makes the molecular weight distribution of these waxes resulting material that narrows down, and, remove low-molecular-weight solid fatty acid, low-molecular-weight solid alcohol, low-molecular-weight solid chemical compound, the resulting material of other impurity.

In addition, the addition of above-mentioned wax is preferably 0.1～20 mass parts with respect to 100 mass parts binding resins, more preferably 1～10 mass parts.And, use 2 kinds to add also passable to wax simultaneously.

In the endothermic curve that the developer that is added with these waxes is measured by DSC, preferably has maximum peak in 60～120 ℃ zone.

When having maximum peak in these scopes, fixation performance, anti-tack are good.During 60 ℃ of maximum peak temperature less thaies, since the plastic effect of wax, the deterioration of developer self memory.When the maximum peak temperature surpassed 120 ℃, fixation performance worsened.

Developer of the present invention is characterised in that and contains magnetic oxide.By in toner-particle, containing magnetic oxide, the surface resistance of toner-particle and the surface resistance at inorganic micro powder end are equated.As a result, giving and accepting of the electric charge between toner-particle surface and the inorganic micro powder end carried out easily, can make that the alleviation effects of aggregation more effectively embodies between particle.

The number average particle diameter of magnetic oxide of the present invention is preferably 0.05～1.00 μ m, more preferably 0.10～0.60 μ m.

In addition, from the viewpoint of the little dispersiveness toner-particle, employed magnetic oxide is preferably octahedra shape or multinuclear shape among the present invention.And then, in order to improve the little dispersiveness of magnetic oxide of the present invention in toner-particle, preferably carry out following processing, that is, the slurry during to manufacturing applies shearing, the magnetic oxide that generates is temporarily broken into pieces.

Among the present invention, with respect to 100 mass parts binding resins, the amount of the magnetic oxide that contains in the preferred toner-particle is 10 to 200 mass parts, is preferably 20 to 170 mass parts, more preferably 30 to 150 mass parts.

Employed developer keeps Positively chargeable among the present invention in order to make, and preferably controls by containing charge control agent.Wherein, charge control agent preferably is at least in triphenylmethane compound, the quaternary ammonium salt a kind.By using these charge control agents,, also can give electric charge to developer rapidly even when high speed printing.And then, by using these charge control agents, can relax aggregation force between developer particle effectively.

Developer of the present invention can add other external additive as required.

The resin microparticle of effect such as the release agent when for example, playing charged assistant, electric conductivity imparting agent, mobility donor, anticaking agent, heat roller fixation, lubricant, lapping compound, inorganic particles etc.

For example,, can list polyvinyl fluoride powder, zinc stearate powder, polyvinylidene fluoride powder etc., wherein preferred polyvinylidene fluoride powder as lubricant.In addition,, can list ceria oxide powder, silicon carbide powder, strontium titanate powder etc., wherein preferred strontium titanate powder as lapping compound.

As mentioned above, in Positively chargeable developer with the Positively chargeable toner-particle that contains binding resin and magnetic oxide at least, by aggregation force between the control developer particle, can easily be controlled at the nothing constraint yield strength under the specific primary consolidation stress.And, by satisfying the nothing constraint yield strength of the present invention's regulation, even can obtain the developer that toner does not worsen yet, has durable stability, picture quality excellence when high speed printing.

In the present invention, make toner-particle and can use following method.By mixers such as Henschel mixer, bowl mill, after abundant mixing such as binding resin, colorant, other adjuvant, after using warm-up mill, kneader, extruder such hot milling machine melting mixing and cooling curing, pulverize and classification, further, fully mix desired additive by mixers such as Henschel mixers as required, can obtain toner of the present invention.

For example, can list Henschel mixer (production of Mitsui mine company) as mixer; Super mixer (production of KAWATA company); Ribocone (production of company of the former making in great river institute); Nauta mixer, Turburizer, Cyclomix (production of Hosokawa Micron company); Spiral Pin mixer (production of Pacific Ocean machine worker company); Loedige mixer (production of MATSUBO company).As mixing roll, can list KRC kneader (tremble company of this ironworker institute produce); Buss is kneader (production of Buss company) altogether; TEM type extruder (Toshiba Machine Co. Ltd's production); TEX twin shaft mixing roll (production of company of JSW); PCM mixing roll (production of company of pond shellfish ironworker institute); Three roller roller mills, mixing mill grinding machine, kneader (aboveground making institute company produce); Kneadex (production of Mitsui mine company); MS formula pressurization kneader, Kneader-Ruder (gloomy mountain makes company of institute and produces); Banbury mixer (production of Kobe Steel, Ltd company).As comminutor, can list airflow milling, Inomizer (production of Hosokawa Micron company); IDS type muller, PJM jet mill (Nippon Pneumatic MFG Co., Ltd. produces); Cross jet mill (tremble company of this ironworker institute produce); Ulmax (NISSO ENGINEERING CO., LTD produces); SK Jet O-Mill (SEISHIN ENTERPRISE Co., Ltd. produces); Criptron (Kawasaki Heavy Industries, Limited's production); Turbo-mill (production of Turbo company); Super Rotor (a day clear engineering corporation produces).As grader, can list Classiel, Micron Classifier, Spedic Classifier (SEISHIN ENTERPRISE Co., Ltd. company produces); Accurate air classifier (a day clear engineering corporation produces); Micron separator, Turboprex (ATP), TSP separator (production of Hosokawa Micron company); Elbow Jet (a day iron ore mining industry company produces), dispersion separator (Nippon Pneumatic Mfg.Co., Ltd. produces); YM Microcut (peace river Itochu produces).As being used to screen employed screening plant such as coarse grain, can list Ultra Sonic (shake flourish industry company produce); Rezona Siev, revolving screen (company of moral longevity work institute); Vibrasonic System (Dalton Co., Ltd produces); Sonicreen (production of Xin Dong industrial group); Turbine sieve (Turbo Kogyo Co., Ltd. produces); Microsifter (Makino mfg.co., 1td. produces); Circular impact screen etc.

Developer of the present invention is more suitable for being used for following image forming method, described image forming method has at least by being formed at developer layer on the developer carrier and will be formed at sub-image and keep the latent electrostatic image developing on the body to form the developing procedure of developer image, and the torque (T) that puts on this developer carrier state that is formed with developer layer under is 0.1Nm≤T≤50Nm.

In addition, developer of the present invention is more suitable for being used for following image forming method, described image forming method with this developer image with connected and carry out transfer printing to the transfer printing material on the endless transfer printing conveyance member that has applied with the voltage of the charged polarity reversed polarity of toner by conveyance, wherein, this endless transfer printing conveyance member is the transfer printing belt, this transfer printing belt is set at this sub-image and keeps the conveyance direction upstream side at position of body butt and the roller more than at least 2 in downstream to support, at the position that keeps the body butt with this sub-image, it is 0%＜i≤5% that this transfer printing belt keeps body diameter d to the intrusion amount i of this photosensitive surface with respect to this sub-image.When being applied to developer of the present invention in such image forming method, even using transfer printing belt high speed and obtaining continuously under the situation of print image for a long time, also can keep the effect that prevents transfer printing blank (transfervoids) steadily in the long term and suppress the effect that the transfer printing belt pollutes.

As mentioned above, in image forming method, keep body, can use the sub-image that possesses as the lower part to keep body: conductive base as this sub-image; The photoconductive layer that comprises amorphous silicon at least on this conductive base; The sealer that comprises amorphous silicon and/or agraphitic carbon and/or amorphous silicon nitride on this photoconductive layer.

Embodiment

Based on following examples the present invention is specifically described.But embodiments of the present invention are not subjected to any qualification of these embodiment.

The Production Example of＜low molecular weight compositions (B-1) 〉

In four-hole boiling flask, drop into 300 mass parts dimethylbenzene, fully replace internal tank, temperature rising reflux then with nitrogen while stirring.

Under this refluxes, with 4 hours droppings 76.0 mass parts styrene, 24.0 mass parts n-butyl acrylates and 2 mass parts, two-tert-butyl peroxide (initiating agents 1; Ten hours half life period temperature: 129 ℃) mixed liquor keeps finishing polymerization in 2 hours then, obtains low-molecular weight polymer solution (B-1).

The Production Example of＜low molecular weight compositions (B-2) 〉

Use 77.0 mass parts styrene, 23.0 mass parts n-butyl acrylates, 2.5 mass parts initiating agents 1, similarly carry out polymerization, obtain low-molecular weight polymer solution B-2 with the Production Example of low molecular weight compositions B-1.

The Production Example of＜low molecular weight compositions (B-3) 〉

Use 73.0 mass parts styrene, 23.0 mass parts n-butyl acrylates, the positive butyl ester of 4.0 mass parts maleic acid lists, 2.5 mass parts initiating agents 1, similarly carry out polymerization, obtain low-molecular weight polymer solution B-3 with the Production Example of low molecular weight compositions B-1.

The Production Example of＜high molecular weight components (A-1) 〉

In four-hole boiling flask, drop into aqueous solution 20 mass parts through the polyvinyl alcohol (PVA) of water 180 mass parts of the degassing and 2 quality %, add 71.0 mass parts styrene, 24.0 mass parts n-butyl acrylates, the positive butyl ester of 5.0 mass parts maleic acid lists, 0.005 mass parts divinylbenzene and 0.1 mass parts 2 then, two (4, the 4-two-tert-butyl peroxide cyclohexyl) propane (initiating agents 2 of 2-; Ten hours half life period temperature: 92 ℃) mixed liquor stirs and makes suspending liquid.

Fully replace flask interior with nitrogen, be warming up to 85 ℃ then, the beginning polymerization.Kept 24 hours down synthermal, and then add 0.1 mass parts benzoyl peroxide (ten hours half life period temperature: 72 ℃).Keep finishing in 12 hours polymerization again.Thereafter, leach this heavy polymer, washing, drying obtain high molecular weight components (A-1).

The Production Example of＜high molecular weight components (A-2) 〉

With the Production Example of high molecular weight components (A-1) similarly, use 70.0 mass parts styrene, 27.0 mass parts n-butyl acrylates, the positive butyl ester of 3.0 mass parts maleic acid lists, 0.005 mass parts divinylbenzene and 1 mass parts initiating agent 2, obtain high molecular weight components (A-2).

The Production Example of＜high molecular weight components (A-3) 〉

In four-hole boiling flask, drop into 300 mass parts dimethylbenzene, fully replace internal tank, temperature rising reflux then with nitrogen while stirring.

Under this refluxes, at first, with the mixed liquor that dripped 81.0 mass parts styrene, 15.0 mass parts n-butyl acrylates and 0.8 mass parts initiating agent 2 in 4 hours.Dripping these moment of 2 hours of mixed liquor, with the mixed liquor that dripped 4.0 mass parts methacrylic acids and 0.2 mass parts initiating agent 2 in 2 hours.After all dripping, kept 2 hours, finish polymerization, obtain high molecular weight components (A-3) solution.

The manufacturing of＜binding resin (C-1) 〉

In four-hole boiling flask, drop into xylene solution 200 mass parts (being equivalent to 60 mass parts low molecular weight compositions) of above-mentioned low molecular weight compositions (B-2), heat up, under refluxing, stir.On the other hand, in another container, drop into above-mentioned high molecular weight components (A-3) solution 200 mass parts (being equivalent to 40 mass parts high molecular weight components), reflux.Under refluxing above-mentioned low molecular weight compositions (B-2) solution and high molecular weight components (A-3) solution are mixed, organic solvent is removed in distillation then, and resin cooling, the curing back of gained are pulverized, and obtains resin (C-1).The rerum natura of gained resin is shown in the table 1.

The manufacturing of＜binding resin (C-2) 〉

In four-hole boiling flask, drop into xylene solution 200 mass parts (being equivalent to 70 mass parts low molecular weight compositions) of above-mentioned low molecular weight compositions (B-1), heat up, under refluxing, stir.In this flask, drop into above-mentioned high molecular weight components (A-2) 30 mass parts, reflux.Under refluxing above-mentioned low molecular weight compositions (B-1) solution and high molecular weight components (A-2) are mixed, organic solvent is removed in distillation then, and resin cooling, the curing back of gained are pulverized, and obtains resin (C-2).The rerum natura of gained resin is shown in the table 1.

The manufacturing of＜binding resin (C-3) 〉

In four-hole boiling flask, drop into xylene solution 200 mass parts (being equivalent to 80 mass parts low molecular weight compositions) of above-mentioned low molecular weight compositions (B-1), heat up, under refluxing, stir.In this flask, drop into above-mentioned high molecular weight components (A-1) 20 mass parts, reflux.Under refluxing above-mentioned low molecular weight compositions (B-1) solution and high molecular weight components (A-1) are mixed, organic solvent is removed in distillation then, and resin cooling, the curing back of gained are pulverized, and obtains resin (C-3).The rerum natura of gained resin is shown in the table 1.

The manufacturing of＜binding resin (C-4) 〉

In four-hole boiling flask, drop into xylene solution 200 mass parts (being equivalent to 70 mass parts low molecular weight compositions) of above-mentioned low molecular weight compositions (B-3), heat up, under refluxing, stir.In this flask, drop into above-mentioned high molecular weight components (A-1) 30 mass parts, reflux.Under refluxing above-mentioned low molecular weight compositions (B-3) solution and high molecular weight components (A-1) are mixed, organic solvent is removed in distillation then, and resin cooling, the curing back of gained are pulverized, and obtains resin (C-4).The rerum natura of gained resin is shown in the table 1.

[embodiment 1]

Binding resin C-1 100 mass parts

Magnetic iron oxide particle (octahedron, number average particle diameter: 90 mass parts 0.20 μ m)

(f-t synthetic wax, rerum natura is shown in the table 2 for wax b.Maximum endotherm peak temperature: 101 ℃, number-average molecular weight: 1500, weight-average molecular weight: 2500) 4 mass parts

Charge control agent A (following triphenylmethane mordant pigment) 2 mass parts

Above-mentioned material with the Henschel mixer premixed, is passed through twin shaft pugging extruder melting mixing then.

[chemical formula 4]

With the mixing thing cooling of gained, after the hammer crusher coarse crushing, pulverize with the atomizer that has used the jet air-flow, use utilized Coanda effect cut apart the micro mist comminuted powder classification of grader with gained more, obtain toner-particle.Measure the zeta potential of this toner-particle, the result, the pH of dispersion liquid is 4, the value of zeta potential is 42mV.With respect to this toner-particle of 100 mass parts, the outside interpolation mixes following 3 kinds of external additives, and the sieve mesh screening with mesh 150 μ m obtains developer 1.

Mother metal (BET specific surface area 200m with respect to 100 mass parts silica micropowders ²/ g), (with the dimethyl silicon oil viscosity=70mm under the silicone oil, amino equivalent=830,25 ℃ of main framing with 17 mass parts amino-modified silicone oils ²(methanol concentration during transmissivity 80% is 75% to the/hydrophobicity silica micropowder a that s) handles, the BET specific surface area is 110m ²/ g) 0.8 mass parts

Alumina particle (zeta potential during pH=4: 36.5mV, BET specific surface area: 100m ²/ g) 0.2 mass parts

Strontium titanates (average 1 particle diameter, the 1.5 μ m of number) 3.0 mass parts

Inner interpolation prescription of toner-particle and developer physics value are documented in the table 3, and the relation of primary consolidation stress and nothing constraint yield strength is shown in Figure 3.

For this developer 1, use commercially available duplicating machine (IR-105, Canon produces) be transformed into 1.5 times print speed, limiting part 104 is adjusted into apart from the surface of developer carrier 102 is the developer shown in Figure 1 of 235 μ m relief widths, (23 ℃ of normal temperature low humidities, 5%RH) environment, ambient temperature and moisture (23 ℃, 60%RH) environment and hot and humid (32 ℃, 80%RH) under the environment, use the test pattern of printing ratio 4%, carry out 200,000 continuous printing test.At this moment, the surplus developer test section is adjusted into developer level always prints test in this developer container about 400g.Put on the torque on the developer carrier 102 of developer of this moment by the torquemeter actual measurement, the result is 0.2Nm.

Image color is estimated

Image color is to use the SPI filtrator to carry out reflection density with Macbeth densimeter (production of Macbeth company) to measure, and measures the square image of 5mm.This evaluation in the early stage, carry out 200,000 the time.

Photographic fog is estimated

Photographic fog is to use reflection of the concentration (Reflectometer model TC-6DS Tokyo electricity look company produces) to carry out, the reflection mean concentration that white background partial reflection concentration worst-case value after image forms is made as the transfer printing material before Ds, image form is made as Dr, Ds-Dr is carried out the evaluation of photographic fog as the photographic fog amount.More for a short time meaning more of numerical value can be suppressed photographic fog.This evaluation in the early stage, carry out 200,000 the time.

The evaluation of picture quality

The evaluation of picture quality also uses above-mentioned image to form testing machine, draws 1 the isolated pattern of 1200dpi under the ambient temperature and moisture environment, with observation by light microscope picture appraisal point repeatability.

A: do not have toner to exceed the phenomenon of sub-image, complete reproduction point fully.

B: have toner to exceed the phenomenon of sub-image a little.

C: the phenomenon that toner exceeds sub-image is many.

The evaluation of consumption of toner

About consumption of toner, also use above-mentioned image to form testing machine after drawing 1000 under the ambient temperature and moisture environment, 4 horizontal line patterns, the sub-image live width of setting 600dpi for are about 190 μ m, the printing rate on 5000 A4 size paper exported is 6% image, and consumption is obtained in the variation of the toning dosage in the developer.

The evaluation of live width

About live width, also use above-mentioned image to form testing machine is described 600dpi at interval with 1cm under the ambient temperature and moisture environment 4 horizontal line pattern sub-images (the about 190 μ m of sub-image live width), to its development, and transfer printing, photographic fixing are to PET system OHP.Use Surfcorder SE-30H (little slope research institute produce),, obtain live width by the width of this profile with the horizontal line that is loaded with toner one side of gained horizontal line pattern image profile as surfaceness.When live width is thicker slightly than sub-image live width, can obtain the highest image of clarity, along with attenuate reductions such as the repeatability of fine rule than sub-image live width.

More than the evaluation result of Ping Jiaing is shown in table 4～6.

In addition, the limiting part 104 that above-mentioned image is formed the developer of testing machine changes to elastomeric element, is 100g/cm at the developer carrier 102 lip-deep pressure that are configured to put on the bed thickness restrictions ²Developer in fill 400g developer 1.Then, the processing speed with 600mm/sec under the ambient temperature and moisture environment makes developer carrier idle running 60 minutes, and the variation of the carried charge before and after the idle running is estimated.In addition, by the torquemeter actual measurement put on this moment developer carrier 102 on torque, the result is 10Nm.

A: the not enough 3mC/kg of the amplitude of variation of the carried charge before and after the idle running

B: the amplitude of variation of the carried charge before and after the idle running is 3～6mC/kg

C: the amplitude of variation of the carried charge before and after the idle running is greater than 6mC/kg

[embodiment 2]

Except with the prescription of table 3 record (about binding resin, with reference to table 1; About wax, with reference to table 2) in addition, make developer 2 similarly to Example 1.The toner-particle that is contained in the developer 2 is dispersed in the water, measures the pH of dispersion liquid, the result is pH=4.The rerum natura of the developer that obtains like this is shown in the table 3.In addition, the result of the test identical with embodiment 1 is shown in table 4～6.

The pH of the dispersion liquid when in addition, being dispersed in the toner-particle of embodiment 3～7, comparative example 1～5 in the water is 4.

[embodiment 3]

Except with the prescription of table 3 record (about binding resin, with reference to table 1; About wax, with reference to table 2) in addition, make developer 3 similarly to Example 1.In addition, as the inorganic micro powder end, the zeta potential the when Zinc oxide particles that replaces alumina particle to use is pH=4 is 30m as 8.3mV, BET specific surface area ²The Zinc oxide particles of/g.The rerum natura of the developer that obtains like this is shown in the table 3.In addition, the result of the test identical with embodiment 1 is shown in table 4～6.

[embodiment 4]

Except with the prescription of table 3 record (about binding resin, with reference to table 1; About wax, with reference to table 2) in addition, make developer 4 similarly to Example 1.In addition, as the inorganic micro powder end, the zeta potential the when magnesium oxide particle that replaces alumina particle to use is pH=4 is 5.3m as 44.3mV, BET specific surface area ²The magnesium oxide particle of/g.The rerum natura of the developer that obtains like this is shown in the table 3.In addition, the result of the test identical with embodiment 1 is shown in table 4～6.

[embodiment 5]

Except with the prescription of table 3 record (about binding resin, with reference to table 1; About wax, with reference to table 2) in addition, make developer 5 similarly to Example 1.In addition, charge control agent B is meant the quaternary ammonium salt with following structure, and the magnetic iron oxide particle of multinuclear shape is that number average particle diameter is the material of 0.19 μ m.In addition, as the inorganic micro powder end, the Zinc oxide particles that replaces alumina particle to use is the Zinc oxide particles that uses among the embodiment 3, and its addition is 0.5 mass parts.And silica micropowder b is with respect to 100 mass parts silica mother metal (BET specific surface area 200m ²/ g), (with the dimethyl silicon oil viscosity=70mm under the silicone oil, amino equivalent=830,25 ℃ of main framing with 15 mass parts amino-modified silicone oils ²/ s) and 2 mass parts amino silicane coupling agents are handled simultaneously and the methanol concentration during transmissivity 80% is 69% hydrophobicity silica micropowder.The rerum natura of the developer that obtains like this is shown in the table 3.In addition, the result of the test identical with embodiment 1 is shown in table 4～6.

[chemical formula 5]

[embodiment 6]

Except with the prescription of table 3 record (about binding resin, with reference to table 1; About wax, with reference to table 2) in addition, make developer 6 similarly to Example 1.And the magnetic iron oxide particle of multinuclear shape is the magnetic iron oxide particle that uses among the embodiment 5.The rerum natura of the developer that obtains like this is shown in the table 3.In addition, the result of the test identical with embodiment 1 is shown in table 4～6.

[embodiment 7]

Except with the prescription of table 3 record (about binding resin, with reference to table 1; About wax, with reference to table 2) and use beyond 2 parts of wax a, the 4 parts of wax b, developer 7 made similarly to Example 1.And as the inorganic micro powder end, the Zinc oxide particles that replaces alumina particle to use is the Zinc oxide particles that uses among the embodiment 3.The rerum natura of the developer that obtains like this is shown in the table 3.In addition, the result of the test identical with embodiment 1 is shown in table 4～6.

[comparative example 1～5]

With the prescription of table 3 record (about binding resin, with reference to table 1; About wax, with reference to table 2), make developer 8～12 similarly to Example 1.The rerum natura of the developer that obtains like this is shown in the table 3.In addition, the result of the test identical with embodiment 1 is shown in table 4～6.And charge control agent C is a nigrosine.In addition, as the inorganic micro powder end, the zeta potential the when titan oxide particles that replaces alumina particle to use is pH=4 is 100m as 2.1mV, BET specific surface area ²The titan oxide particles of/g.Further, as the inorganic micro powder end, the zeta potential the when silica granule that replaces alumina particle to use is pH=4 is-9.5mV, BET specific surface area be 50m ²The silica granule of/g.

Table 1

Table 2

	Kind	Maximum endotherm peak temperature (℃)	Number-average molecular weight	Weight-average molecular weight
					Wax a	Paraffin	75	800	1100
Wax b	F-t synthetic wax	101	1500	2500
					Wax c	Higher alcohol wax (hydroxyl value: 70)	100	1000	1800

Table 4

Hot and humid (32 ℃/evaluation result under 80%RH)

Table 5

(23 ℃/evaluation result under 60%RH) of ambient temperature and moistures

Table 6

(23 ℃/evaluation result under 5%RH) of normal temperature low humidities

The Production Example of＜low molecular weight compositions (E-1) 〉

In four-hole boiling flask, drop into 300 mass parts dimethylbenzene, fully replace internal tank with nitrogen while stirring, heat up then, reflux.

Under this refluxes, with the mixed liquor that dripped 75.0 mass parts styrene, 25.0 mass parts n-butyl acrylates and 2.0 mass parts, two-tert-butyl peroxide (initiating agent 1) in 4 hours, keep then finishing polymerization in 2 hours, obtain low-molecular weight polymer solution (E-1).

The Production Example of＜low molecular weight compositions (E-2) 〉

Use 79.0 mass parts styrene, 21.0 mass parts n-butyl acrylates, 1.0 mass parts initiating agents 1, similarly carry out polymerization, obtain low-molecular weight polymer solution E-2 with the Production Example of low molecular weight compositions E-1.

The Production Example of＜low molecular weight compositions (E-3) 〉

Use 77.0 mass parts styrene, 23.0 mass parts n-butyl acrylates, 2.0 mass parts initiating agents 1, similarly carry out polymerization, obtain low-molecular weight polymer solution E-3 with the Production Example of low molecular weight compositions E-1.

The Production Example of＜low molecular weight compositions (E-4) 〉

Use 72.0 mass parts styrene, 24.0 mass parts n-butyl acrylates, 4.0 mass parts acrylic acid, 2.0 mass parts initiating agents 1, similarly carry out polymerization, obtain low-molecular weight polymer solution E-4 with the Production Example of low molecular weight compositions E-1.

The Production Example of＜low molecular weight compositions (E-5) 〉

Use 74.0 mass parts styrene, 24.0 mass parts n-butyl acrylates, 1.5 mass parts initiating agents 1, similarly carry out polymerization, obtain low-molecular weight polymer solution E-5 with the Production Example of low molecular weight compositions E-1.

The Production Example of＜high molecular weight components (D-1) 〉

In four-hole boiling flask, drop into 300 mass parts dimethylbenzene, fully replace internal tank with nitrogen while stirring, heat up then, reflux.

Under this refluxes, at first, with 4 hours droppings 80.0 mass parts styrene, 16.0 mass parts n-butyl acrylates and 2.0 mass parts 2, the mixed liquor of two (4, the 4-two-tert-butyl peroxide cyclohexyl) propane (initiating agent 2) of 2-, 5.0 mass parts methacrylic acids.After all dripping, keep finishing polymerization in 2 hours, obtain high molecular weight components (D-1) solution.

The Production Example of＜high molecular weight components (D-2) 〉

Use the mixed liquor of 81.0 mass parts styrene, 16.0 mass parts n-butyl acrylates, 2.0 mass parts initiating agents 2 and 4.0 mass parts methacrylic acids, similarly carry out polymerization with the Production Example of high molecular weight components D-1, obtain high molecular weight components (D-2) solution.

The Production Example of＜high molecular weight components (D-3) 〉

Use the mixed liquor of 79.0 mass parts styrene, 16.0 mass parts n-butyl acrylates, 2.0 mass parts initiating agents 2 and 6.0 mass parts methacrylic acids, similarly carry out polymerization with the Production Example of high molecular weight components D-1, obtain high molecular weight components (D-3) solution.

The Production Example of＜high molecular weight components (D-4) 〉

Use the mixed liquor of 82.0 mass parts styrene, 17.5 mass parts n-butyl acrylates, 0.6 mass parts divinylbenzene, 0.4 mass parts initiating agent 2 and the positive butyl ester of 2.0 mass parts maleic acid lists, similarly carry out polymerization with the Production Example of high molecular weight components D-1, obtain high molecular weight components (D-4) solution.

The Production Example of＜high molecular weight components (D-5) 〉

In four-hole boiling flask, drop into the aqueous solution of 180 mass parts through the polyvinyl alcohol (PVA) of the water of the degassing and 20 mass parts, 2 quality %, the mixed liquor that adds 73.0 mass parts styrene, 23.0 mass parts n-butyl acrylates, the positive butyl ester of 7.0 mass parts maleic acid lists, 0.005 mass parts divinylbenzene and 0.8 mass parts initiating agent 2 then stirs and makes suspending liquid.

Fully replace flask interior with nitrogen, be warmed up to 85 ℃ then, the beginning polymerization.Kept 24 hours down synthermal, and then add 0.1 mass parts benzoyl peroxide (ten hours half life period temperature; 72 ℃).Keep finishing in 12 hours polymerization again.Thereafter, leach this heavy polymer, washing, drying obtain high molecular weight components (D-5).

The Production Example of＜high molecular weight components (D-6) 〉

Use the mixed liquor of 76.0 mass parts styrene, 26.0 mass parts n-butyl acrylates, 0.005 mass parts divinylbenzene, 1.0 mass parts initiating agents 2 and 7.0 mass parts methacrylic acids, similarly carry out polymerization with the Production Example of high molecular weight components D-1, obtain high molecular weight components (D-6) solution.

The Production Example of＜high molecular weight components (D-7) 〉

With the Production Example of high molecular weight components (D-5) similarly, use 70.0 mass parts styrene, 24.0 mass parts n-butyl acrylates, the positive butyl ester of 4.0 mass parts maleic acid lists, 0.005 mass parts divinylbenzene and 1.5 mass parts initiating agents 2, obtain high molecular weight components (D-7).

The manufacturing of＜binding resin (F-1) 〉

In four-hole boiling flask, drop into xylene solution 200 mass parts (being equivalent to 60 mass parts low molecular weight compositions) of above-mentioned low molecular weight compositions (E-1), heat up, under refluxing, stir.On the other hand, in another container, drop into above-mentioned high molecular weight components (D-1) solution 200 mass parts (being equivalent to 40 mass parts high molecular weight components), reflux.Above-mentioned low molecular weight compositions (E-1) solution and high molecular weight components (D-1) solution are mixed under refluxing, and organic solvent is removed in distillation then, and resin cooling, the curing back of gained are pulverized.With Henschel mixer with potpourri 95 mass parts of this low molecular weight compositions and high molecular weight components with contain the glycidyl vinylite (styrene-propene acid glycidyl ester copolymer, weight-average molecular weight: 14000, epoxide number: 0.1eq/kg) 5 mass parts are mixed, carry out cross-linking reaction with two-axis extruder at 200 ℃ then, cool off with the cooling velocity of 1 ℃/min then, pulverize, obtain binding resin (F-1) thereafter.

The manufacturing of＜binding resin (F-2), (F-3) 〉

Use above-mentioned high molecular weight components (D-2), (D-3), similarly obtain binding resin (F-2), (F-3) with the Production Example of binding resin (F-1).

The manufacturing of＜binding resin (F-4) 〉

In four-hole boiling flask, drop into xylene solution 200 mass parts (being equivalent to 70 mass parts low molecular weight compositions) of above-mentioned low molecular weight compositions (E-2), heat up, under refluxing, stir.In this flask, drop into the above-mentioned high molecular weight components of 30 mass parts (D-4), reflux.Above-mentioned low molecular weight compositions (E-2) solution and high molecular weight components (D-4) are mixed under refluxing, and organic solvent is removed in distillation then, and resin cooling, the curing back of gained are pulverized, and obtains binding resin (F-4).

The manufacturing of＜binding resin (F-5) 〉

Use xylene solution 200 mass parts (being equivalent to 80 mass parts low molecular weight compositions) and above-mentioned high molecular weight components (D-5) 20 mass parts of above-mentioned low molecular weight compositions (E-3), similarly obtain binding resin (F-5) with the Production Example of binding resin (F-4).

The manufacturing of＜binding resin (F-6) 〉

Use xylene solution 200 mass parts (being equivalent to 80 mass parts low molecular weight compositions) and above-mentioned high molecular weight components (D-6) 20 mass parts of above-mentioned low molecular weight compositions (E-4), similarly obtain binding resin (F-6) with the Production Example of binding resin (F-4).

The manufacturing of＜binding resin (F-7) 〉

Use xylene solution 200 mass parts (being equivalent to 70 mass parts low molecular weight compositions) and above-mentioned high molecular weight components (D-7) 30 mass parts of above-mentioned low molecular weight compositions (E-5), similarly obtain binding resin (F-7) with the Production Example of binding resin (F-4).

Rerum naturas such as the acid number of above-mentioned binding resin (F-1)～(F-7), peak molecular weight are shown in the table 7.

The Production Example at＜fine magnesium oxide micro-powder end 1 〉

Implemented the water-soluble magnesium salt of purification processes in advance with respect to 1 equivalent, mixed 0.90 equivalent alkaline matters down, sent out and answer at 30 ℃, thereafter, with reactant and reaction mother liquor together at about 60kg/cm ²Add depress with 100 ℃ the heating about 4 hours, obtain magnesium hydroxide.In Kan Saer (kanthal) stove, burnt till this magnesium hydroxide 3 hours with 1450 ℃.The comminutor that uses band air current classifying mechanism to burned material pulverize, classification, obtain fine magnesium oxide micro-powder end 1.The physics value at the fine magnesium oxide micro-powder end 1 of gained is shown in the table 8.

The Production Example at＜fine magnesium oxide micro-powder end 2 〉

Except firing time in the Production Example 1 at fine magnesium oxide micro-powder end is 2 hours, similarly obtain fine magnesium oxide micro-powder end 2 with Production Example 1.The physics value at the fine magnesium oxide micro-powder end 2 of gained is shown in the table 8.

The Production Example at＜fine magnesium oxide micro-powder end 3 〉

Except firing temperature is 1150 ℃ in the Production Example 1 at fine magnesium oxide micro-powder end, similarly obtain fine magnesium oxide micro-powder end 3 with Production Example 1.The physics value at the fine magnesium oxide micro-powder end 3 of gained is shown in the table 8.

The Production Example at＜fine magnesium oxide micro-powder end 4 〉

Except firing temperature is 1750 ℃ in the Production Example 1 at fine magnesium oxide micro-powder end, similarly obtain fine magnesium oxide micro-powder end 4 with Production Example 1.The physics value at the fine magnesium oxide micro-powder end 4 of gained is shown in the table 8.

The Production Example at＜fine magnesium oxide micro-powder end 5 〉

Except in the Production Example 1 at fine magnesium oxide micro-powder end, adding 0.70 equivalent alkaline matter, similarly obtain fine magnesium oxide micro-powder end 5 with Production Example 1.The physics value at the fine magnesium oxide micro-powder end 5 of gained is shown in the table 8.

The Production Example at＜fine magnesium oxide micro-powder end 6 〉

Except in the Production Example 1 at fine magnesium oxide micro-powder end, firing temperature being made as 1750 ℃, firing time being made as 2 hours, similarly obtain fine magnesium oxide micro-powder end 6 with Production Example 1.The physics value at the fine magnesium oxide micro-powder end 6 of gained is shown in the table 8.

The Production Example at＜fine magnesium oxide micro-powder end 7 〉

Except in the Production Example 6 at fine magnesium oxide micro-powder end, adding 0.60 equivalent alkaline matter, similarly obtain fine magnesium oxide micro-powder end 7 with Production Example 6.The physics value at the fine magnesium oxide micro-powder end 7 of gained is shown in the table 8.

The Production Example at＜fine magnesium oxide micro-powder end 8 〉

Except in the Production Example 3 at fine magnesium oxide micro-powder end, use seawater as the magnesium source, use unslaked lime as alkali source, similarly obtain seawater method fine magnesium oxide micro-powder end 8.The physics value of gained is shown in the table 8.

The Production Example at＜fine magnesium oxide micro-powder end 9 〉

Use vapour phase oxidation process magnesium oxide (Ube Material Industries, Ltd. produces 500A) as fine magnesium oxide micro-powder end 9.

The fine magnesium oxide micro-powder end 1～9 of using among the present invention all is that (2 θ ± 0.2deg) there is the fine magnesium oxide micro-powder end at peak at the 42.9deg place for Bragg angle in CuK α characteristic X-ray diffraction.The physics value at fine magnesium oxide micro-powder end 1～9 is shown in the table 8.

[embodiment 8]

Binding resin F-1 100 mass parts

Magnetic iron oxide particle (octahedron, number average particle diameter: 90 mass parts 0.20 μ m)

Wax b (f-t synthetic wax) 4 mass parts

Aforementioned charge control agent A (triphenylmethane mordant pigment) 2 mass parts

Above-mentioned material with the Henschel mixer premixed, is passed through twin shaft pugging extruder melting mixing then.With the mixing thing cooling of gained, with the hammer crusher coarse crushing, pulverize with the atomizer that has used the jet air-flow then, use and utilized the grader of cutting apart of Coanda effect that the micro mist comminuted powder of gained is carried out classification more, obtain toner-particle.Measure the zeta potential of this toner-particle, the pH of dispersion liquid is 4 as a result, and the value of zeta potential is 41.0mV.

Use Henschel mixer under condition 1 (1700rpm, 5 minutes), mix following external additive with respect to outside interpolation of this toner-particle of 100 mass parts, the sieve mesh screening with mesh 150 μ m obtains developer 13.Prescription is added in the inside of developer and rerum natura is documented in the table 9.

Fine magnesium oxide micro-powder end 1 is 0.2 mass parts

Aforementioned hydrophobicity silica micropowder a is 0.8 mass parts

The strontium titanates that uses among the embodiment 1 is 3.0 mass parts

For this developer 13, transform commercially available duplicating machine (iR-105, Canon produce) as 1.3 times print speed, under the environment of the environment of 23 ℃, the environment of 5%RH and 23 ℃, 60%RH and 30 ℃, 80%RH, use the test pattern of printing ratio 4% to carry out 250,000 continuous printing.

The evaluation of image color

Image color is to use the SPI filtrator to carry out reflection density with Macbeth densimeter (production of Macbeth company) to measure and measure the square image of 5mm.This evaluation in the early stage, carry out 250,000 the time.Its evaluation result is shown in table 10～12.

The evaluation of photographic fog

Photographic fog uses reflection of the concentration (Reflectometer model TC-6DS, Tokyo electricity look company produce) to carry out, white background reflection density worst-case value after image forms is that the reflection mean concentration of the transfer printing material before Ds, image form is Dr, Ds-Dr is carried out the evaluation of photographic fog as the photographic fog amount.This evaluation in the early stage, carry out 250,000 the time.Its evaluation result is shown in table 10～12.

The evaluation of hangover

The evaluation of hangover is under each environment, initial stage and drawing after 250,000, and use above-mentioned image to form testing machine live width is being adjusted under the condition of 170 μ m, draw the pattern that 4 horizontal line is printed on 15 space.With 100 times of this image augmentation, in extended image, number goes out the number that produces hangover on square interior viewed 3 horizontal lines of 2.5mm with optical microscope.

A: do not produce

B: 3 of less thaies

C: 3～7 of less thaies

D: 7～15 of less thaies

More than E:15

[embodiment 9,10]

Except the prescription of table 9 record (about binding resin, with reference to table 7; About wax, with reference to table 2; About magnesium oxide, with reference to table 8) in addition, make developer 14,15 similarly to Example 8.The toner-particle that is contained in the developer 14,15 is dispersed in the water, measures the pH of dispersion liquid, the result is pH=4.The rerum natura of the developer that obtains like this is shown in the table 9.In addition, the result who tests similarly to Example 8 is shown in table 10～12.

In addition, when being dispersed in the toner-particle of the embodiment 11～17 of back, comparative example 6～9 in the water, the pH of dispersion liquid is 4.

[embodiment 11]

Except the prescription of table 9 record (about binding resin, with reference to table 7; About wax, with reference to table 2; About magnesium oxide, with reference to table 8) in addition, make developer 16 similarly to Example 8.In addition, the magnetic iron oxide particle of multinuclear shape is the magnetic iron oxide particle that uses among the embodiment 5.The rerum natura of the developer that obtains like this is shown in the table 9.In addition, the result who tests similarly to Example 8 is shown in table 10～12.

[embodiment 12]

Except the prescription of table 9 record (about binding resin, with reference to table 7; About wax, with reference to table 2; About magnesium oxide, with reference to table 8) and will utilize the outside adding conditional of Henschel mixer to become condition 2 (1300rpm, 1 minute) and in addition, make developer 17 similarly to Example 8.In addition, the magnetic iron oxide particle of multinuclear shape is the magnetic iron oxide particle that uses among the embodiment 5.The rerum natura of the developer that obtains like this is shown in the table 9.In addition, the result who tests similarly to Example 8 is shown in table 10～12.

[embodiment 13]

Except the prescription of table 9 record (about binding resin, with reference to table 7; About wax, with reference to table 2; About magnesium oxide, with reference to table 8) and utilize the outside adding conditional of Henschel mixer to become condition 3 (2000rpm, 8 minutes) and in addition, make developer 18 similarly to Example 8.In addition, the magnetic iron oxide particle of multinuclear shape is the magnetic iron oxide particle that uses among the embodiment 5.The rerum natura of the developer that obtains like this is shown in the table 9.In addition, the result who tests similarly to Example 8 is shown in table 10～12.

[embodiment 14]

Except the prescription of table 9 record (about binding resin, with reference to table 7; About wax, with reference to table 2; About magnesium oxide, with reference to table 8) and use beyond 4 parts of wax a and the 2 parts of wax b, developer 19 made similarly to Example 8.The rerum natura of the developer that obtains like this is shown in the table 9.In addition, the result who tests similarly to Example 8 is shown in table 10～12.

[embodiment 15]

Except the prescription of table 9 record (about binding resin, with reference to table 7; About wax, with reference to table 2; About magnesium oxide, with reference to table 8) in addition, make developer 20 similarly to Example 8.In addition, the magnetic iron oxide particle of multinuclear shape is the magnetic iron oxide particle that uses among the embodiment 5.The rerum natura of the developer that obtains like this is shown in the table 9.In addition, the result who tests similarly to Example 8 is shown in table 10～12.

[embodiment 16]

Except the prescription of table 9 record (about binding resin, with reference to table 7; About wax, with reference to table 2; About magnesium oxide, with reference to table 8) in addition, make developer 21 similarly to Example 8.In addition, the magnetic iron oxide particle of multinuclear shape is the magnetic iron oxide particle that uses among the embodiment 5.The rerum natura of the developer that obtains like this is shown in the table 9.In addition, the result who tests similarly to Example 8 is shown in table 10～12.

[embodiment 17]

Except the prescription of table 9 record (about binding resin, with reference to table 7; About wax, with reference to table 2; About magnesium oxide, with reference to table 8) in addition, make developer 22 similarly to Example 8.In addition, the magnetic iron oxide particle of multinuclear shape is the magnetic iron oxide particle that uses among the embodiment 5.The rerum natura of the developer that obtains like this is shown in the table 9.In addition, the result who tests similarly to Example 8 is shown in table 10～12.

[comparative example 6～9]

Except the prescription of table 9 record (about binding resin, with reference to table 7; About wax, with reference to table 2; About magnesium oxide, with reference to table 8) in addition, make developer 23～26 similarly to Example 8.The rerum natura of the developer that obtains like this is shown in the table 9.In addition, the result who tests similarly to Example 8 is shown in table 10～12.In addition, using number average particle diameter is the magnetic of the magnetic of 0.20 μ m as sphere.As acidifying tin micropowder, use that particle diameter is that 0.30 μ m, isoelectric point are 6.6, the zeta potential during pH=4 is 35.0m for-12.1mV, BET specific surface area ²The acidifying tin micropowder of/g.As the titanium oxide fine powder end, use that particle diameter is that 0.27 μ m, isoelectric point are 5.0, the zeta potential during pH=4 is 7.1m as 1.5mV, BET specific surface area ²The titanium oxide fine powder end of/g.

Table 7

Table 8

The fine magnesium oxide micro-powder end	1	2	3	4	5	6	7	8	9
										X ray peak half breadth (deg)	0.274	0.321	0.295	0.302	0.269	0.314	0.342	0.416	0.372
MgO content (quality %)	99.98	98.50	99.98	99.98	99.98	99.20	98.20	97.98	99.98
										Volume average particle size (μ m)	1.1	1.3	0.3	1.8	1.2	1.4	1.4	0.52	0.05
1/2 times of accumulated value (volume %) that particle diameter is following	5.1	6.2	6.1	8.6	6.7	6.7	6.7	10.2	5.1
										2 times of accumulated values (volume %) that particle diameter is above	5.8	6.6	6.4	8.2	6.3	6.3	6.3	11.3	5.3
Isoelectric point	13.0	12.8	13.1	12.3	9.2	13.6	8.4	12.3	12.5
										Zeta potential during pH4 (mV)	41.5	38.9	40.2	40.5	37.2	39.5	36.8	35.2	40.0
BET specific surface area (m 2/g)	3.7	3.2	3.5	3.1	3.4	3.1	1.2	24	33.4

Table 10

Hot and humid (30 ℃/evaluation result under 80%RH)

Table 11

(23 ℃/evaluation result under 60%RH) of ambient temperature and moistures

Table 12

(23 ℃/evaluation result under 5%RH) of normal temperature low humidities

[embodiment 18]

The transfer device periphery of commercially available digital copier iR105 (Canon's production) is transformed into the transfer printing belt-type shown in Fig. 5, changes photoreceptor into following photoreceptor 1, use after the processing speed of machine body is transformed into 660mm/sec.Print speed is 110cpm.

Photoreceptor 1: on cylindric aluminum substrate, the sealer that be laminated with photoconductive layer that the electric charge that is made of the a-Si:H film that has mixed boron injects trapping layer, is made of the a-Si:H film that has mixed boron, is made of the silicon fiml that comprises silicon and carbon (a-SiC:H) obtains, external diameter is that the a-Si of the Positively chargeable of 108mm is a photoreceptor

In the present embodiment, developing procedure uses the developer that is equipped on the iR105, and adopts by the mode of magnetic mono-component jump visualization way with the electrostatic latent image discharged-area development on the photoreceptor 11.

The top layer material of transfer printing belt is used neoprene, and the transfer printing belt is set at 3% to the intrusion amount i of photoreceptor.In addition, the bias voltage roller is applied bias voltage with the charged polarity opposite polarity of toner.

In addition, in the sketch of transfer device shown in Figure 5, for the purpose of simplifying the description, be drawn as transfer printing belt 12, but in the neutralization that starts to work of image processing system quits work, be disconnected from each other with respect to photoreceptor 11 structure of face contact always.In addition, in the present embodiment, it is identical with the peripheral speed of photoreceptor that the peripheral speed of transfer printing belt is set at.In Fig. 5, symbol 11 is that driven roller, symbol 14 are transfer printing material for clearer, symbol 18 for hairbrush, symbol 19 for high-voltage power supply, symbol 17 for bias voltage roller, symbol 16 for driven voller, symbol 15 for sub-image keeps body (photoreceptor), symbol 12 for transfer printing belt, symbol 13.

Use developer 1, implements following long duration test: send mode each 300000 of printing continuously so that A4 is horizontal the character image of image rate 4% by the order of 23 ℃/50%RH environment, 23 ℃/5%RH environment and 32 ℃/90%RH environment.As a result, under arbitrary environment, can obtain to suppress well the pollution of transfer printing belt, the also excellent result of transfer printing quality (transfer printing blank, bad, the transfer printing skew of transfer printing).

The application requires to enjoy the right of priority of Japanese patent application No. 2004-335421 that applied on November 19th, 2004 and the Japanese patent application No. 2004-335385 that was applied on November 19th, 2004, and quotes the part of its content as the application.

Claims (23)

1. Positively chargeable developer is characterized in that, it has the Positively chargeable toner-particle at least, and this Positively chargeable toner-particle contains binding resin, magnetic oxide at least,

The nothing constraint yield strength U of this developer when primary consolidation stress 5.0kPa _5kPaBe 0.1kPa≤U _5kPa≤ 2.5kPa,

The nothing constraint yield strength U of this developer when primary consolidation stress 20.0kPa _20kPaBe 2.5kPa≤U _20kPa≤ 5.5kPa.

2. according to Positively chargeable developer according to claim 1, it is characterized in that this developer is the outside developer that adds the inorganic micro powder end in this Positively chargeable toner-particle.

3. Positively chargeable developer according to claim 2 is characterized in that, described inorganic micro powder end is for being selected from the micropowder of at least a kind of oxide in zinc paste, aluminium oxide, the magnesium oxide.

4. Positively chargeable developer according to claim 3, it is characterized in that, this inorganic micro powder end is the fine magnesium oxide micro-powder end, and this fine magnesium oxide micro-powder end is Bragg angle 2 θ=42.9 ° ± 0.2 ° crystallographic system of locating the peak in CuK α characteristic X-ray diffraction, and is below 0.40 ° at the half breadth at this Bragg angle 2 θ=42.9 ° ± 0.2 ° X-ray diffraction peak of locating.

5. Positively chargeable developer according to claim 4 is characterized in that, the volume average particle size A at this fine magnesium oxide micro-powder end is 0.1 μ m≤A≤2.0 μ m,

Size-grade distribution is: the volume distributed median accumulated value with fine magnesium oxide micro-powder end of the following particle diameter of 1/2 times of particle diameter of this volume average particle size is below the 10 volume %, and the volume distributed median accumulated value with fine magnesium oxide micro-powder end of the above particle diameter of 2 times of particle diameters of this volume average particle size is below the 10 volume %.

6. Positively chargeable developer according to claim 4 is characterized in that, the isoelectric point at this fine magnesium oxide micro-powder end is 8～14.

7. Positively chargeable developer according to claim 4 is characterized in that, the specific surface area at this fine magnesium oxide micro-powder end is 1.0～15.0m ²/ g.

8. Positively chargeable developer according to claim 4 is characterized in that, the MgO content in this fine magnesium oxide micro-powder end is more than 98.00%.

9. Positively chargeable developer according to claim 2 is characterized in that, the content B at this inorganic micro powder end is 0.01 quality %≤B≤2.00 quality % based on whole developers.

10. Positively chargeable developer according to claim 2 is characterized in that, the ionization rate C at this inorganic micro powder end is 0.1%≤C≤5.0%.

11. Positively chargeable developer according to claim 2, it is characterized in that the zeta potential that the Positively chargeable toner-particle is distributed to this Positively chargeable toner-particle under the pH of the dispersion liquid that forms in the water is below the 40mV with difference with the zeta potential at this inorganic micro powder end under the pH.

12. Positively chargeable developer according to claim 3 is characterized in that, this developer also contains the silica micropowder except that containing the inorganic micro powder end.

13. Positively chargeable developer according to claim 12, it is characterized in that, when measuring this silica micropowder to the wettability of methanol mixed solvent with the transmissivity of 780nm wavelength light, transmissivity is that 80% o'clock methanol concentration D is 65 volume %≤D≤80 volume %.

14. Positively chargeable developer according to claim 2 is characterized in that, the acid number D of this developer _AvBe 0.5mgKOH/g≤D _Av≤ 20.0mgKOH/g.

15. Positively chargeable developer according to claim 1 is characterized in that, is in the size-grade distribution of benchmark at this developer with the number what measure with 256 passages by Coulter counter, half breadth Y satisfies following formula to peak granularity X

2.06×X-9.0≤Y≤2.06×X-7.5。

16. Positively chargeable developer according to claim 1, it is characterized in that, in the molecular weight distribution of the solvable composition of tetrahydrofuran in this developer by gel permeation chromatography GPC mensuration, at molecular weight is that there is main peak in the zone below 30000 more than 3000, and the peak area of molecular weight below 100,000 is more than the 70 quality % with respect to all peak areas.

17. Positively chargeable developer according to claim 1, it is characterized in that, when by the Soxhlet extractron that uses tetrahydrofuran THF this developer being carried out 16 hours extraction, the insoluble composition of the THF of this binding resin composition is the insoluble composition of 0.1 quality %≤THF≤50.0 quality %.

18. Positively chargeable developer according to claim 1 is characterized in that, this binding resin has the polystyrene copolymer resins at least.

19. Positively chargeable developer according to claim 1 is characterized in that, this developer has charge control agent, and this charge control agent is at least a kind in triphenylmethane compound, the quaternary ammonium salt.

20. Positively chargeable developer according to claim 1 is characterized in that, this magnetic oxide has octahedra shape and/or multinuclear shape.

21. Positively chargeable developer according to claim 1 is characterized in that, the content E of this magnetic iron oxide particle is 20 mass parts≤E≤200 mass parts with respect to 100 mass parts binding resins.

22. image forming method is characterized in that, it has developing procedure at least, and this developing procedure keeps the electrostatic latent image on the body to develop to being formed at sub-image, thereby forms the developer image by being formed at the developer layer on the developer carrier,

Wherein, the torque T that puts on this developer carrier of the state that is formed with developer layer is 0.1Nm≤T≤50Nm

This developer is the described Positively chargeable developer of claim 1.

23. image forming method according to claim 22; it is characterized in that, this sub-image keep body possess conductive base, at the photoconductive layer that comprises amorphous silicon at least on this conductive base, the sealer that comprises amorphous silicon and/or agraphitic carbon and/or amorphous silicon nitride on this photoconductive layer.

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